diff --git a/src/main/java/com/jozufozu/flywheel/api/instance/BlockEntityInstance.java b/src/main/java/com/jozufozu/flywheel/api/instance/BlockEntityInstance.java
index 0ea0acd7e..0fb3a750e 100644
--- a/src/main/java/com/jozufozu/flywheel/api/instance/BlockEntityInstance.java
+++ b/src/main/java/com/jozufozu/flywheel/api/instance/BlockEntityInstance.java
@@ -2,10 +2,10 @@ package com.jozufozu.flywheel.api.instance;
 
 import java.util.List;
 
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 
 import net.minecraft.world.level.block.entity.BlockEntity;
 
 public interface BlockEntityInstance<T extends BlockEntity> extends Instance {
-	List<InstancedPart> getCrumblingParts();
+	List<InstancePart> getCrumblingParts();
 }
diff --git a/src/main/java/com/jozufozu/flywheel/api/instance/DynamicInstance.java b/src/main/java/com/jozufozu/flywheel/api/instance/DynamicInstance.java
index 36c8088b8..4f9835cb3 100644
--- a/src/main/java/com/jozufozu/flywheel/api/instance/DynamicInstance.java
+++ b/src/main/java/com/jozufozu/flywheel/api/instance/DynamicInstance.java
@@ -2,7 +2,7 @@ package com.jozufozu.flywheel.api.instance;
 
 import org.joml.FrustumIntersection;
 
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.instancer.Instancer;
 
 /**
@@ -20,7 +20,7 @@ public interface DynamicInstance extends Instance {
 	 * <br>
 	 * <em>DISPATCHED IN PARALLEL</em>, don't attempt to mutate anything outside this instance.
 	 * <br>
-	 * {@link Instancer}/{@link InstancedPart} creation/acquisition is safe here.
+	 * {@link Instancer}/{@link InstancePart} creation/acquisition is safe here.
 	 */
 	void beginFrame();
 
diff --git a/src/main/java/com/jozufozu/flywheel/api/instance/TickableInstance.java b/src/main/java/com/jozufozu/flywheel/api/instance/TickableInstance.java
index 3e8a24ba8..e0c8fd77d 100644
--- a/src/main/java/com/jozufozu/flywheel/api/instance/TickableInstance.java
+++ b/src/main/java/com/jozufozu/flywheel/api/instance/TickableInstance.java
@@ -1,6 +1,6 @@
 package com.jozufozu.flywheel.api.instance;
 
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.instancer.Instancer;
 
 /**
@@ -25,7 +25,7 @@ public interface TickableInstance extends Instance {
 	 * Called every tick, and after initialization.<p>
 	 * <em>DISPATCHED IN PARALLEL</em>, don't attempt to mutate anything outside of this instance
 	 * without proper synchronization.<p>
-	 * {@link Instancer}/{@link InstancedPart} creation/acquisition is safe here.
+	 * {@link Instancer}/{@link InstancePart} creation/acquisition is safe here.
 	 */
 	void tick();
 
diff --git a/src/main/java/com/jozufozu/flywheel/api/instancer/Handle.java b/src/main/java/com/jozufozu/flywheel/api/instancer/Handle.java
new file mode 100644
index 000000000..208c73673
--- /dev/null
+++ b/src/main/java/com/jozufozu/flywheel/api/instancer/Handle.java
@@ -0,0 +1,8 @@
+package com.jozufozu.flywheel.api.instancer;
+
+public interface Handle {
+
+	void setChanged();
+
+	void setDeleted();
+}
diff --git a/src/main/java/com/jozufozu/flywheel/api/instancer/InstancePart.java b/src/main/java/com/jozufozu/flywheel/api/instancer/InstancePart.java
new file mode 100644
index 000000000..ba6144f49
--- /dev/null
+++ b/src/main/java/com/jozufozu/flywheel/api/instancer/InstancePart.java
@@ -0,0 +1,10 @@
+package com.jozufozu.flywheel.api.instancer;
+
+import com.jozufozu.flywheel.api.struct.StructType;
+
+public interface InstancePart {
+	StructType<?> type();
+
+	@Deprecated
+	InstancePart copy(Handle handle);
+}
diff --git a/src/main/java/com/jozufozu/flywheel/api/instancer/InstancedPart.java b/src/main/java/com/jozufozu/flywheel/api/instancer/InstancedPart.java
deleted file mode 100644
index e06799ba1..000000000
--- a/src/main/java/com/jozufozu/flywheel/api/instancer/InstancedPart.java
+++ /dev/null
@@ -1,46 +0,0 @@
-package com.jozufozu.flywheel.api.instancer;
-
-import com.jozufozu.flywheel.api.struct.StructType;
-
-public abstract class InstancedPart {
-
-	public final StructType<?> type;
-	private Instancer<?> owner;
-
-	private boolean dirty;
-	private boolean removed;
-
-	protected InstancedPart(StructType<?> type) {
-		this.type = type;
-	}
-
-	public final void markDirty() {
-		dirty = true;
-		owner.notifyDirty();
-	}
-
-	public final void delete() {
-		removed = true;
-		owner.notifyRemoval();
-	}
-
-	public final boolean checkDirtyAndClear() {
-		boolean wasDirty = dirty;
-		dirty = false;
-		return wasDirty;
-	}
-
-	public final boolean isRemoved() {
-		return removed;
-	}
-
-	public Instancer<?> getOwner() {
-		return owner;
-	}
-
-	public void setOwner(Instancer<?> owner) {
-		this.owner = owner;
-	}
-
-    public abstract InstancedPart copy();
-}
diff --git a/src/main/java/com/jozufozu/flywheel/api/instancer/Instancer.java b/src/main/java/com/jozufozu/flywheel/api/instancer/Instancer.java
index 58ef8a8f7..9be9e5633 100644
--- a/src/main/java/com/jozufozu/flywheel/api/instancer/Instancer.java
+++ b/src/main/java/com/jozufozu/flywheel/api/instancer/Instancer.java
@@ -16,45 +16,20 @@ package com.jozufozu.flywheel.api.instancer;
  *     because it means the properties of your model don't have to be re-evaluated every frame.
  * </p>
  *
- * @param <D> the data that represents a copy of the instanced model.
+ * @param <P> the data that represents a copy of the instanced model.
  */
-public interface Instancer<D extends InstancedPart> {
+public interface Instancer<P extends InstancePart> {
 	/**
 	 * @return a handle to a new copy of this model.
 	 */
-	D createInstance();
-
-	/**
-	 * Copy a data from another Instancer to this.
-	 * This has the effect of swapping out one model for another.
-	 * @param inOther the data associated with a different model.
-	 */
-	void stealInstance(D inOther);
-
-	/**
-	 * Notify the Instancer that some of its data needs updating.
-	 *
-	 * <p>
-	 *     This might be ignored, depending on the implementation. For the GPUInstancer, this triggers a scan of all
-	 *     instances.
-	 * </p>
-	 */
-	void notifyDirty();
-
-	/**
-	 * Notify the Instances that some of its data should be removed.
-	 *
-	 * <p>
-	 *     By the time the next frame is drawn, the instanceData passed will no longer be considered for rendering.
-	 * </p>
-	 */
-	void notifyRemoval();
+	P createInstance();
 
 	/**
 	 * Populate arr with new instances of this model.
+	 *
 	 * @param arr An array to fill.
 	 */
-	default void createInstances(D[] arr) {
+	default void createInstances(P[] arr) {
 		for (int i = 0; i < arr.length; i++) {
 			arr[i] = createInstance();
 		}
diff --git a/src/main/java/com/jozufozu/flywheel/api/instancer/InstancerProvider.java b/src/main/java/com/jozufozu/flywheel/api/instancer/InstancerProvider.java
index 74338c8fb..21ea65f18 100644
--- a/src/main/java/com/jozufozu/flywheel/api/instancer/InstancerProvider.java
+++ b/src/main/java/com/jozufozu/flywheel/api/instancer/InstancerProvider.java
@@ -10,5 +10,5 @@ public interface InstancerProvider {
 	 *
 	 * @return An instancer for the given struct type, model, and render stage.
 	 */
-	<D extends InstancedPart> Instancer<D> instancer(StructType<D> type, Model model, RenderStage stage);
+	<P extends InstancePart> Instancer<P> instancer(StructType<P> type, Model model, RenderStage stage);
 }
diff --git a/src/main/java/com/jozufozu/flywheel/api/struct/StructType.java b/src/main/java/com/jozufozu/flywheel/api/struct/StructType.java
index f867d4df2..c0a0bf002 100644
--- a/src/main/java/com/jozufozu/flywheel/api/struct/StructType.java
+++ b/src/main/java/com/jozufozu/flywheel/api/struct/StructType.java
@@ -1,6 +1,7 @@
 package com.jozufozu.flywheel.api.struct;
 
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.Handle;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.layout.BufferLayout;
 import com.jozufozu.flywheel.api.registry.Registry;
 import com.jozufozu.flywheel.api.vertex.MutableVertexList;
@@ -11,29 +12,31 @@ import net.minecraft.resources.ResourceLocation;
 
 /**
  * A StructType contains metadata for a specific instance struct that Flywheel can interface with.
- * @param <S> The java representation of the instance struct.
+ *
+ * @param <P> The java representation of the instance struct.
  */
-public interface StructType<S extends InstancedPart> {
+public interface StructType<P extends InstancePart> {
 	static Registry<StructType<?>> REGISTRY = RegistryImpl.create();
 
 	/**
+	 * @param handle A handle that allows you to mark the instance as dirty or deleted.
 	 * @return A new, zeroed instance of S.
 	 */
-	S create();
+	P create(Handle handle);
 
 	/**
 	 * @return The layout of S when buffered.
 	 */
 	BufferLayout getLayout();
 
-	StructWriter<S> getWriter();
+	StructWriter<P> getWriter();
 
 	ResourceLocation instanceShader();
 
-	VertexTransformer<S> getVertexTransformer();
+	VertexTransformer<P> getVertexTransformer();
 
-	interface VertexTransformer<S extends InstancedPart> {
-		void transform(MutableVertexList vertexList, S struct, ClientLevel level);
+	interface VertexTransformer<P extends InstancePart> {
+		void transform(MutableVertexList vertexList, P struct, ClientLevel level);
 	}
 
 }
diff --git a/src/main/java/com/jozufozu/flywheel/api/struct/StructWriter.java b/src/main/java/com/jozufozu/flywheel/api/struct/StructWriter.java
index 21caf4adc..55468838f 100644
--- a/src/main/java/com/jozufozu/flywheel/api/struct/StructWriter.java
+++ b/src/main/java/com/jozufozu/flywheel/api/struct/StructWriter.java
@@ -1,14 +1,14 @@
 package com.jozufozu.flywheel.api.struct;
 
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 
 /**
  * StructWriters can quickly consume many instances of S and write them to some memory address.
  */
-public interface StructWriter<S extends InstancedPart> {
+public interface StructWriter<P extends InstancePart> {
 	/**
 	 * Write the given struct to the given memory address.
 	 */
-	void write(final long ptr, final S struct);
+	void write(final long ptr, final P struct);
 
 }
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/AbstractInstancer.java b/src/main/java/com/jozufozu/flywheel/backend/engine/AbstractInstancer.java
index bc7f515b1..6ec625409 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/AbstractInstancer.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/AbstractInstancer.java
@@ -4,18 +4,24 @@ import java.util.ArrayList;
 import java.util.BitSet;
 import java.util.List;
 
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.instancer.Instancer;
 import com.jozufozu.flywheel.api.struct.StructType;
 
-public abstract class AbstractInstancer<D extends InstancedPart> implements Instancer<D> {
+public abstract class AbstractInstancer<P extends InstancePart> implements Instancer<P> {
 
-	public final StructType<D> type;
-	protected final ArrayList<D> data = new ArrayList<>();
+	public final StructType<P> type;
 
-	protected boolean anyToRemove;
+	// Lock for all instance data, only needs to be used in methods that may run on the TaskExecutor.
+	protected final Object lock = new Object();
+	protected final ArrayList<P> data = new ArrayList<>();
+	protected final ArrayList<HandleImpl> handles = new ArrayList<>();
 
-	protected AbstractInstancer(StructType<D> type) {
+	// TODO: atomic bitset?
+	protected final BitSet changed = new BitSet();
+	protected final BitSet deleted = new BitSet();
+
+	protected AbstractInstancer(StructType<P> type) {
 		this.type = type;
 	}
 
@@ -23,100 +29,92 @@ public abstract class AbstractInstancer<D extends InstancedPart> implements Inst
 	 * @return a handle to a new copy of this model.
 	 */
 	@Override
-	public D createInstance() {
-		return _add(type.create());
-	}
+	public P createInstance() {
+		synchronized (lock) {
+			var i = data.size();
+			var handle = new HandleImpl(this, i);
+			P instanceData = type.create(handle);
 
-	/**
-	 * Copy a data from another Instancer to this.
-	 * <p>
-	 * This has the effect of swapping out one model for another.
-	 * @param inOther the data associated with a different model.
-	 */
-	@Override
-	public void stealInstance(D inOther) {
-		if (inOther.getOwner() == this) return;
-
-		// Changing the owner reference will delete it in the other instancer
-		inOther.getOwner()
-				.notifyRemoval();
-		_add(inOther);
-	}
-
-	@Override
-	public void notifyRemoval() {
-		anyToRemove = true;
+			data.add(instanceData);
+			handles.add(handle);
+			changed.set(i);
+			return instanceData;
+		}
 	}
 
 	/**
 	 * Clear all instance data without freeing resources.
 	 */
 	public void clear() {
+		handles.forEach(HandleImpl::clear);
 		data.clear();
-		anyToRemove = true;
+		handles.clear();
+		changed.clear();
+		deleted.clear();
 	}
 
 	public int getInstanceCount() {
 		return data.size();
 	}
 
-	public List<D> getRange(int start, int end) {
+	public List<P> getRange(int start, int end) {
 		return data.subList(start, end);
 	}
 
-	public List<D> getAll() {
+	public List<P> getAll() {
 		return data;
 	}
 
 	protected void removeDeletedInstances() {
 		// Figure out which elements are to be removed.
 		final int oldSize = this.data.size();
-		int removeCount = 0;
-		final BitSet removeSet = new BitSet(oldSize);
-		for (int i = 0; i < oldSize; i++) {
-			final D element = this.data.get(i);
-			if (element.isRemoved() || element.getOwner() != this) {
-				removeSet.set(i);
-				removeCount++;
-			}
-		}
+		int removeCount = deleted.cardinality();
 
 		final int newSize = oldSize - removeCount;
 
 		// shift surviving elements left over the spaces left by removed elements
 		for (int i = 0, j = 0; (i < oldSize) && (j < newSize); i++, j++) {
-			i = removeSet.nextClearBit(i);
+			i = deleted.nextClearBit(i);
 
 			if (i != j) {
-				D element = data.get(i);
+				var handle = handles.get(i);
+				P element = data.get(i);
+
+				handles.set(j, handle);
 				data.set(j, element);
-				// Marking the data dirty marks us dirty too.
-				// Perhaps there will be some wasted cycles, but the JVM should be able to
-				// generate code that moves the repeated segment out of the loop.
-				element.markDirty();
+
+				handle.setIndex(j);
+				changed.set(j);
 			}
 		}
 
+		deleted.clear();
 		data.subList(newSize, oldSize)
 				.clear();
-
+		handles.subList(newSize, oldSize)
+				.clear();
 	}
 
-	private D _add(D instanceData) {
-		instanceData.setOwner(this);
-
-		instanceData.markDirty();
-		synchronized (data) {
-			data.add(instanceData);
-		}
-
-		return instanceData;
-	}
-
-	public abstract void delete();
-
 	@Override
 	public String toString() {
 		return "Instancer[" + getInstanceCount() + ']';
 	}
+
+	public void notifyDirty(int index) {
+		if (index < 0 || index >= getInstanceCount()) {
+			return;
+		}
+		synchronized (lock) {
+			changed.set(index);
+		}
+	}
+
+	public void notifyRemoval(int index) {
+		if (index < 0 || index >= getInstanceCount()) {
+			return;
+		}
+		synchronized (lock) {
+			deleted.set(index);
+		}
+	}
 }
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/HandleImpl.java b/src/main/java/com/jozufozu/flywheel/backend/engine/HandleImpl.java
new file mode 100644
index 000000000..915ef8249
--- /dev/null
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/HandleImpl.java
@@ -0,0 +1,32 @@
+package com.jozufozu.flywheel.backend.engine;
+
+import com.jozufozu.flywheel.api.instancer.Handle;
+
+public class HandleImpl implements Handle {
+
+	private final AbstractInstancer<?> instancer;
+	private int index;
+
+	public HandleImpl(AbstractInstancer<?> instancer, int index) {
+		this.instancer = instancer;
+		this.index = index;
+	}
+
+	@Override
+	public void setChanged() {
+		instancer.notifyDirty(index);
+	}
+
+	@Override
+	public void setDeleted() {
+		instancer.notifyRemoval(index);
+	}
+
+	public void setIndex(int i) {
+		index = i;
+	}
+
+	public void clear() {
+		index = -1;
+	}
+}
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/InstancerKey.java b/src/main/java/com/jozufozu/flywheel/backend/engine/InstancerKey.java
index 8be8b6116..39fa9840a 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/InstancerKey.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/InstancerKey.java
@@ -1,9 +1,9 @@
 package com.jozufozu.flywheel.backend.engine;
 
 import com.jozufozu.flywheel.api.event.RenderStage;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.model.Model;
 import com.jozufozu.flywheel.api.struct.StructType;
 
-public record InstancerKey<D extends InstancedPart>(StructType<D> type, Model model, RenderStage stage) {
+public record InstancerKey<P extends InstancePart>(StructType<P> type, Model model, RenderStage stage) {
 }
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/batching/BatchingEngine.java b/src/main/java/com/jozufozu/flywheel/backend/engine/batching/BatchingEngine.java
index bf55fbde6..3e62c61ff 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/batching/BatchingEngine.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/batching/BatchingEngine.java
@@ -5,7 +5,7 @@ import java.util.List;
 import com.jozufozu.flywheel.api.backend.Engine;
 import com.jozufozu.flywheel.api.event.RenderContext;
 import com.jozufozu.flywheel.api.event.RenderStage;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.instancer.Instancer;
 import com.jozufozu.flywheel.api.model.Model;
 import com.jozufozu.flywheel.api.struct.StructType;
@@ -24,7 +24,7 @@ public class BatchingEngine implements Engine {
 	private final BatchingDrawTracker drawTracker = new BatchingDrawTracker();
 
 	@Override
-	public <D extends InstancedPart> Instancer<D> instancer(StructType<D> type, Model model, RenderStage stage) {
+	public <P extends InstancePart> Instancer<P> instancer(StructType<P> type, Model model, RenderStage stage) {
 		return transformManager.getInstancer(type, model, stage);
 	}
 
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/batching/BatchingTransformManager.java b/src/main/java/com/jozufozu/flywheel/backend/engine/batching/BatchingTransformManager.java
index bc3240d27..b07d78952 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/batching/BatchingTransformManager.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/batching/BatchingTransformManager.java
@@ -15,7 +15,7 @@ import com.google.common.collect.ArrayListMultimap;
 import com.google.common.collect.ImmutableListMultimap;
 import com.google.common.collect.ListMultimap;
 import com.jozufozu.flywheel.api.event.RenderStage;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.instancer.Instancer;
 import com.jozufozu.flywheel.api.model.Mesh;
 import com.jozufozu.flywheel.api.model.Model;
@@ -42,9 +42,9 @@ public class BatchingTransformManager {
 	}
 
 	@SuppressWarnings("unchecked")
-	public <D extends InstancedPart> Instancer<D> getInstancer(StructType<D> type, Model model, RenderStage stage) {
-		InstancerKey<D> key = new InstancerKey<>(type, model, stage);
-		CPUInstancer<D> instancer = (CPUInstancer<D>) instancers.get(key);
+	public <P extends InstancePart> Instancer<P> getInstancer(StructType<P> type, Model model, RenderStage stage) {
+		InstancerKey<P> key = new InstancerKey<>(type, model, stage);
+		CPUInstancer<P> instancer = (CPUInstancer<P>) instancers.get(key);
 		if (instancer == null) {
 			instancer = new CPUInstancer<>(type);
 			instancers.put(key, instancer);
@@ -71,7 +71,6 @@ public class BatchingTransformManager {
 				.forEach(BatchedMeshPool::delete);
 		meshPools.clear();
 
-		initializedInstancers.forEach(CPUInstancer::delete);
 		initializedInstancers.clear();
 	}
 
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/batching/CPUInstancer.java b/src/main/java/com/jozufozu/flywheel/backend/engine/batching/CPUInstancer.java
index 29b17dc2f..99306a267 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/batching/CPUInstancer.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/batching/CPUInstancer.java
@@ -1,29 +1,18 @@
 package com.jozufozu.flywheel.backend.engine.batching;
 
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.struct.StructType;
 import com.jozufozu.flywheel.backend.engine.AbstractInstancer;
 
-public class CPUInstancer<D extends InstancedPart> extends AbstractInstancer<D> {
+public class CPUInstancer<P extends InstancePart> extends AbstractInstancer<P> {
 
-	public CPUInstancer(StructType<D> type) {
+	public CPUInstancer(StructType<P> type) {
 		super(type);
 	}
 
 	void update() {
-		if (anyToRemove) {
-			data.removeIf(InstancedPart::isRemoved);
-			anyToRemove = false;
+		if (!deleted.isEmpty()) {
+			removeDeletedInstances();
 		}
 	}
-
-	@Override
-	public void notifyDirty() {
-		// noop
-	}
-
-	@Override
-	public void delete() {
-		// noop
-	}
 }
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/batching/TransformCall.java b/src/main/java/com/jozufozu/flywheel/backend/engine/batching/TransformCall.java
index 5aebed403..003337564 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/batching/TransformCall.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/batching/TransformCall.java
@@ -2,7 +2,7 @@ package com.jozufozu.flywheel.backend.engine.batching;
 
 import java.util.List;
 
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.material.Material;
 import com.jozufozu.flywheel.api.struct.StructType;
 import com.jozufozu.flywheel.api.task.TaskExecutor;
@@ -16,15 +16,15 @@ import com.mojang.math.Vector4f;
 
 import net.minecraft.client.multiplayer.ClientLevel;
 
-public class TransformCall<D extends InstancedPart> {
-	private final CPUInstancer<D> instancer;
+public class TransformCall<P extends InstancePart> {
+	private final CPUInstancer<P> instancer;
 	private final Material material;
 	private final BatchedMeshPool.BufferedMesh mesh;
 
 	private final int meshVertexCount;
 	private final int meshByteSize;
 
-	public TransformCall(CPUInstancer<D> instancer, Material material, BatchedMeshPool.BufferedMesh mesh) {
+	public TransformCall(CPUInstancer<P> instancer, Material material, BatchedMeshPool.BufferedMesh mesh) {
 		this.instancer = instancer;
 		this.material = material;
 		this.mesh = mesh;
@@ -65,18 +65,18 @@ public class TransformCall<D extends InstancedPart> {
 		transformList(vertexList, instancer.getAll(), matrices, level);
 	}
 
-	private void transformList(ReusableVertexList vertexList, List<D> parts, PoseStack.Pose matrices, ClientLevel level) {
+	private void transformList(ReusableVertexList vertexList, List<P> parts, PoseStack.Pose matrices, ClientLevel level) {
 		long anchorPtr = vertexList.ptr();
 		int totalVertexCount = vertexList.vertexCount();
 
 		vertexList.vertexCount(meshVertexCount);
 
-		StructType.VertexTransformer<D> structVertexTransformer = instancer.type.getVertexTransformer();
+		StructType.VertexTransformer<P> structVertexTransformer = instancer.type.getVertexTransformer();
 
-		for (D d : parts) {
+		for (P p : parts) {
 			mesh.copyTo(vertexList.ptr());
 
-			structVertexTransformer.transform(vertexList, d, level);
+			structVertexTransformer.transform(vertexList, p, level);
 
 			vertexList.ptr(vertexList.ptr() + meshByteSize);
 		}
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectCullingGroup.java b/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectCullingGroup.java
index f60427a53..b5f9bed66 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectCullingGroup.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectCullingGroup.java
@@ -12,7 +12,7 @@ import static org.lwjgl.opengl.GL45.glVertexArrayElementBuffer;
 import static org.lwjgl.opengl.GL45.glVertexArrayVertexBuffer;
 
 import com.jozufozu.flywheel.api.event.RenderStage;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.struct.StructType;
 import com.jozufozu.flywheel.api.vertex.VertexType;
 import com.jozufozu.flywheel.backend.compile.FlwCompiler;
@@ -22,7 +22,7 @@ import com.jozufozu.flywheel.lib.context.Contexts;
 import com.jozufozu.flywheel.lib.pipeline.Pipelines;
 import com.jozufozu.flywheel.lib.util.QuadConverter;
 
-public class IndirectCullingGroup<T extends InstancedPart> {
+public class IndirectCullingGroup<P extends InstancePart> {
 
 	private static final int BARRIER_BITS = GL_SHADER_STORAGE_BARRIER_BIT | GL_COMMAND_BARRIER_BIT;
 
@@ -38,13 +38,13 @@ public class IndirectCullingGroup<T extends InstancedPart> {
 
 	int vertexArray;
 
-	final IndirectDrawSet<T> drawSet = new IndirectDrawSet<>();
+	final IndirectDrawSet<P> drawSet = new IndirectDrawSet<>();
 
 	private boolean hasCulledThisFrame;
 	private boolean needsMemoryBarrier;
 	private int instanceCountThisFrame;
 
-	IndirectCullingGroup(StructType<T> structType, VertexType vertexType) {
+	IndirectCullingGroup(StructType<P> structType, VertexType vertexType) {
 		this.vertexType = vertexType;
 
 		objectStride = structType.getLayout()
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectDraw.java b/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectDraw.java
index fa2bbed67..bbc352f4c 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectDraw.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectDraw.java
@@ -3,12 +3,12 @@ package com.jozufozu.flywheel.backend.engine.indirect;
 import org.lwjgl.system.MemoryUtil;
 
 import com.jozufozu.flywheel.api.event.RenderStage;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.material.Material;
 import com.jozufozu.flywheel.lib.material.MaterialIndices;
 
-public final class IndirectDraw<T extends InstancedPart> {
-	private final IndirectInstancer<T> instancer;
+public final class IndirectDraw<P extends InstancePart> {
+	private final IndirectInstancer<P> instancer;
 	private final IndirectMeshPool.BufferedMesh mesh;
 	private final Material material;
 	private final RenderStage stage;
@@ -19,7 +19,7 @@ public final class IndirectDraw<T extends InstancedPart> {
 
 	boolean needsFullWrite = true;
 
-	IndirectDraw(IndirectInstancer<T> instancer, Material material, RenderStage stage, IndirectMeshPool.BufferedMesh mesh) {
+	IndirectDraw(IndirectInstancer<P> instancer, Material material, RenderStage stage, IndirectMeshPool.BufferedMesh mesh) {
 		this.instancer = instancer;
 		this.material = material;
 		this.stage = stage;
@@ -42,10 +42,9 @@ public final class IndirectDraw<T extends InstancedPart> {
 	void writeObjects(long objectPtr, long batchIDPtr, int batchID) {
 		if (needsFullWrite) {
 			instancer.writeFull(objectPtr, batchIDPtr, batchID);
-		} else if (instancer.anyToUpdate) {
+		} else {
 			instancer.writeSparse(objectPtr, batchIDPtr, batchID);
 		}
-		instancer.anyToUpdate = false;
 	}
 
 	public void writeIndirectCommand(long ptr) {
@@ -63,7 +62,7 @@ public final class IndirectDraw<T extends InstancedPart> {
 
 	}
 
-	public IndirectInstancer<T> instancer() {
+	public IndirectInstancer<P> instancer() {
 		return instancer;
 	}
 
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectDrawManager.java b/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectDrawManager.java
index 316335d83..73eb23973 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectDrawManager.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectDrawManager.java
@@ -6,7 +6,7 @@ import java.util.List;
 import java.util.Map;
 
 import com.jozufozu.flywheel.api.event.RenderStage;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.instancer.Instancer;
 import com.jozufozu.flywheel.api.model.Model;
 import com.jozufozu.flywheel.api.struct.StructType;
@@ -22,9 +22,9 @@ public class IndirectDrawManager {
 	public final Map<Pair<StructType<?>, VertexType>, IndirectCullingGroup<?>> renderLists = new HashMap<>();
 
 	@SuppressWarnings("unchecked")
-	public <D extends InstancedPart> Instancer<D> getInstancer(StructType<D> type, Model model, RenderStage stage) {
-		InstancerKey<D> key = new InstancerKey<>(type, model, stage);
-		IndirectInstancer<D> instancer = (IndirectInstancer<D>) instancers.get(key);
+	public <P extends InstancePart> Instancer<P> getInstancer(StructType<P> type, Model model, RenderStage stage) {
+		InstancerKey<P> key = new InstancerKey<>(type, model, stage);
+		IndirectInstancer<P> instancer = (IndirectInstancer<P>) instancers.get(key);
 		if (instancer == null) {
 			instancer = new IndirectInstancer<>(type);
 			instancers.put(key, instancer);
@@ -51,7 +51,6 @@ public class IndirectDrawManager {
 				.forEach(IndirectCullingGroup::delete);
 		renderLists.clear();
 
-		initializedInstancers.forEach(IndirectInstancer::delete);
 		initializedInstancers.clear();
 	}
 
@@ -60,13 +59,13 @@ public class IndirectDrawManager {
 	}
 
 	@SuppressWarnings("unchecked")
-	private <D extends InstancedPart> void add(IndirectInstancer<D> instancer, Model model, RenderStage stage) {
+	private <P extends InstancePart> void add(IndirectInstancer<P> instancer, Model model, RenderStage stage) {
 		var meshes = model.getMeshes();
 		for (var entry : meshes.entrySet()) {
 			var material = entry.getKey();
 			var mesh = entry.getValue();
 
-			var indirectList = (IndirectCullingGroup<D>) renderLists.computeIfAbsent(Pair.of(instancer.type, mesh.getVertexType()), p -> new IndirectCullingGroup<>(p.first(), p.second()));
+			var indirectList = (IndirectCullingGroup<P>) renderLists.computeIfAbsent(Pair.of(instancer.type, mesh.getVertexType()), p -> new IndirectCullingGroup<>(p.first(), p.second()));
 
 			indirectList.drawSet.add(instancer, material, stage, indirectList.meshPool.alloc(mesh));
 
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectDrawSet.java b/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectDrawSet.java
index dd80b96e2..8fe598553 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectDrawSet.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectDrawSet.java
@@ -11,14 +11,14 @@ import java.util.List;
 import java.util.Map;
 
 import com.jozufozu.flywheel.api.event.RenderStage;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.material.Material;
 import com.jozufozu.flywheel.lib.material.MaterialIndices;
 import com.jozufozu.flywheel.util.Textures;
 
-public class IndirectDrawSet<T extends InstancedPart> {
+public class IndirectDrawSet<P extends InstancePart> {
 
-	final List<IndirectDraw<T>> indirectDraws = new ArrayList<>();
+	final List<IndirectDraw<P>> indirectDraws = new ArrayList<>();
 
 	final Map<RenderStage, List<MultiDraw>> multiDraws = new EnumMap<>(RenderStage.class);
 
@@ -30,7 +30,7 @@ public class IndirectDrawSet<T extends InstancedPart> {
 		return indirectDraws.size();
 	}
 
-	public void add(IndirectInstancer<T> instancer, Material material, RenderStage stage, IndirectMeshPool.BufferedMesh bufferedMesh) {
+	public void add(IndirectInstancer<P> instancer, Material material, RenderStage stage, IndirectMeshPool.BufferedMesh bufferedMesh) {
 		indirectDraws.add(new IndirectDraw<>(instancer, material, stage, bufferedMesh));
 		determineMultiDraws();
 	}
@@ -49,7 +49,7 @@ public class IndirectDrawSet<T extends InstancedPart> {
 		// TODO: Better material equality. Really we only need to bin by the results of the setup method.
 		multiDraws.clear();
 		// sort by stage, then material
-		indirectDraws.sort(Comparator.comparing(IndirectDraw<T>::stage)
+		indirectDraws.sort(Comparator.comparing(IndirectDraw<P>::stage)
 				.thenComparing(draw -> MaterialIndices.getMaterialIndex(draw.material())));
 
 		for (int start = 0, i = 0; i < indirectDraws.size(); i++) {
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectEngine.java b/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectEngine.java
index 207766137..be3e9bb30 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectEngine.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectEngine.java
@@ -7,7 +7,7 @@ import org.lwjgl.opengl.GL32;
 import com.jozufozu.flywheel.api.backend.Engine;
 import com.jozufozu.flywheel.api.event.RenderContext;
 import com.jozufozu.flywheel.api.event.RenderStage;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.instancer.Instancer;
 import com.jozufozu.flywheel.api.model.Model;
 import com.jozufozu.flywheel.api.struct.StructType;
@@ -34,7 +34,7 @@ public class IndirectEngine implements Engine {
 	}
 
 	@Override
-	public <D extends InstancedPart> Instancer<D> instancer(StructType<D> type, Model model, RenderStage stage) {
+	public <P extends InstancePart> Instancer<P> instancer(StructType<P> type, Model model, RenderStage stage) {
 		return drawManager.getInstancer(type, model, stage);
 	}
 
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectInstancer.java b/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectInstancer.java
index b21bb0c89..4d50bafc5 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectInstancer.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectInstancer.java
@@ -2,54 +2,45 @@ package com.jozufozu.flywheel.backend.engine.indirect;
 
 import org.lwjgl.system.MemoryUtil;
 
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.struct.StructType;
 import com.jozufozu.flywheel.api.struct.StructWriter;
 import com.jozufozu.flywheel.backend.engine.AbstractInstancer;
 
-public class IndirectInstancer<D extends InstancedPart> extends AbstractInstancer<D> {
+public class IndirectInstancer<P extends InstancePart> extends AbstractInstancer<P> {
 
 	private final long objectStride;
-	private final StructWriter<D> writer;
+	private final StructWriter<P> writer;
 	int instanceCount = 0;
 
-	boolean anyToUpdate;
-
-	public IndirectInstancer(StructType<D> type) {
+	public IndirectInstancer(StructType<P> type) {
 		super(type);
 		this.objectStride = type.getLayout()
 				.getStride();
 		writer = type.getWriter();
 	}
 
-	@Override
-	public void notifyDirty() {
-		anyToUpdate = true;
-	}
-
 	public boolean isEmpty() {
-		return !anyToUpdate && !anyToRemove && instanceCount == 0;
+		return changed.isEmpty() && deleted.isEmpty() && instanceCount == 0;
 	}
 
 	void update() {
-		if (anyToRemove) {
+		if (!deleted.isEmpty()) {
 			removeDeletedInstances();
 		}
 
 		instanceCount = data.size();
-
-		anyToRemove = false;
 	}
 
 	public void writeSparse(long objectPtr, long batchIDPtr, int batchID) {
-		for (int i = 0, size = data.size(); i < size; i++) {
-			final var element = data.get(i);
-			if (element.checkDirtyAndClear()) {
-				writer.write(objectPtr + i * objectStride, element);
+		final int size = data.size();
 
-				MemoryUtil.memPutInt(batchIDPtr + i * IndirectBuffers.INT_SIZE, batchID);
-			}
+		for (int i = changed.nextSetBit(0); i >= 0 && i < size; i = changed.nextSetBit(i + 1)) {
+			writer.write(objectPtr + i * objectStride, data.get(i));
+
+			MemoryUtil.memPutInt(batchIDPtr + i * IndirectBuffers.INT_SIZE, batchID);
 		}
+		changed.clear();
 	}
 
 	public void writeFull(long objectPtr, long batchIDPtr, int batchID) {
@@ -62,10 +53,6 @@ public class IndirectInstancer<D extends InstancedPart> extends AbstractInstance
 			MemoryUtil.memPutInt(batchIDPtr, batchID);
 			batchIDPtr += IndirectBuffers.INT_SIZE;
 		}
-	}
-
-	@Override
-	public void delete() {
-		// noop
+		changed.clear();
 	}
 }
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/instancing/GPUInstancer.java b/src/main/java/com/jozufozu/flywheel/backend/engine/instancing/GPUInstancer.java
index ce7058c5b..55b48a75c 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/instancing/GPUInstancer.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/instancing/GPUInstancer.java
@@ -4,7 +4,7 @@ import java.util.HashSet;
 import java.util.Set;
 
 import com.jozufozu.flywheel.Flywheel;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.layout.BufferLayout;
 import com.jozufozu.flywheel.api.struct.StructType;
 import com.jozufozu.flywheel.api.struct.StructWriter;
@@ -15,25 +15,18 @@ import com.jozufozu.flywheel.gl.buffer.GlBufferType;
 import com.jozufozu.flywheel.gl.buffer.GlBufferUsage;
 import com.jozufozu.flywheel.gl.buffer.MappedBuffer;
 
-public class GPUInstancer<D extends InstancedPart> extends AbstractInstancer<D> {
+public class GPUInstancer<P extends InstancePart> extends AbstractInstancer<P> {
 
 	final BufferLayout instanceFormat;
-	final StructType<D> structType;
 	final Set<GlVertexArray> boundTo = new HashSet<>();
 	GlBuffer vbo;
 	int glInstanceCount = 0;
 
 	boolean anyToUpdate;
 
-	public GPUInstancer(StructType<D> type) {
+	public GPUInstancer(StructType<P> type) {
 		super(type);
 		this.instanceFormat = type.getLayout();
-		this.structType = type;
-	}
-
-	@Override
-	public void notifyDirty() {
-		anyToUpdate = true;
 	}
 
 	public void init() {
@@ -46,11 +39,11 @@ public class GPUInstancer<D extends InstancedPart> extends AbstractInstancer<D>
 	}
 
 	public boolean isEmpty() {
-		return !anyToUpdate && !anyToRemove && glInstanceCount == 0;
+		return deleted.isEmpty() && changed.isEmpty() && glInstanceCount == 0;
 	}
 
 	void update() {
-		if (anyToRemove) {
+		if (!deleted.isEmpty()) {
 			removeDeletedInstances();
 		}
 
@@ -59,13 +52,11 @@ public class GPUInstancer<D extends InstancedPart> extends AbstractInstancer<D>
 			boundTo.clear();
 		}
 
-		if (anyToUpdate) {
+		if (!changed.isEmpty()) {
 			clearAndUpdateBuffer();
 		}
 
 		glInstanceCount = data.size();
-
-		anyToRemove = anyToUpdate = false;
 	}
 
 	private void clearAndUpdateBuffer() {
@@ -78,15 +69,14 @@ public class GPUInstancer<D extends InstancedPart> extends AbstractInstancer<D>
 
 			if (size > 0) {
 				final long ptr = buf.getPtr();
-				final long stride = structType.getLayout().getStride();
-				final StructWriter<D> writer = structType.getWriter();
+				final long stride = type.getLayout()
+						.getStride();
+				final StructWriter<P> writer = type.getWriter();
 
-				for (int i = 0; i < size; i++) {
-					final D element = data.get(i);
-					if (element.checkDirtyAndClear()) {
-						writer.write(ptr + i * stride, element);
-					}
+				for (int i = changed.nextSetBit(0); i >= 0 && i < size; i = changed.nextSetBit(i + 1)) {
+					writer.write(ptr + i * stride, data.get(i));
 				}
+				changed.clear();
 			}
 		} catch (Exception e) {
 			Flywheel.LOGGER.error("Error updating GPUInstancer:", e);
@@ -104,7 +94,6 @@ public class GPUInstancer<D extends InstancedPart> extends AbstractInstancer<D>
 		return vbo.ensureCapacity(requiredSize);
 	}
 
-	@Override
 	public void delete() {
 		vbo.delete();
 		vbo = null;
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/instancing/InstancingDrawManager.java b/src/main/java/com/jozufozu/flywheel/backend/engine/instancing/InstancingDrawManager.java
index 89cf04c4c..10c3fd563 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/instancing/InstancingDrawManager.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/instancing/InstancingDrawManager.java
@@ -14,7 +14,7 @@ import com.google.common.collect.ArrayListMultimap;
 import com.google.common.collect.ImmutableListMultimap;
 import com.google.common.collect.ListMultimap;
 import com.jozufozu.flywheel.api.event.RenderStage;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.instancer.Instancer;
 import com.jozufozu.flywheel.api.model.Mesh;
 import com.jozufozu.flywheel.api.model.Model;
@@ -35,9 +35,9 @@ public class InstancingDrawManager {
 	}
 
 	@SuppressWarnings("unchecked")
-	public <D extends InstancedPart> Instancer<D> getInstancer(StructType<D> type, Model model, RenderStage stage) {
-		InstancerKey<D> key = new InstancerKey<>(type, model, stage);
-		GPUInstancer<D> instancer = (GPUInstancer<D>) instancers.get(key);
+	public <P extends InstancePart> Instancer<P> getInstancer(StructType<P> type, Model model, RenderStage stage) {
+		InstancerKey<P> key = new InstancerKey<>(type, model, stage);
+		GPUInstancer<P> instancer = (GPUInstancer<P>) instancers.get(key);
 		if (instancer == null) {
 			instancer = new GPUInstancer<>(type);
 			instancers.put(key, instancer);
diff --git a/src/main/java/com/jozufozu/flywheel/backend/engine/instancing/InstancingEngine.java b/src/main/java/com/jozufozu/flywheel/backend/engine/instancing/InstancingEngine.java
index 639d3e771..8cfbb174b 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/engine/instancing/InstancingEngine.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/engine/instancing/InstancingEngine.java
@@ -8,7 +8,7 @@ import com.jozufozu.flywheel.api.backend.Engine;
 import com.jozufozu.flywheel.api.context.Context;
 import com.jozufozu.flywheel.api.event.RenderContext;
 import com.jozufozu.flywheel.api.event.RenderStage;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.api.instancer.Instancer;
 import com.jozufozu.flywheel.api.model.Model;
 import com.jozufozu.flywheel.api.struct.StructType;
@@ -41,7 +41,7 @@ public class InstancingEngine implements Engine {
 	}
 
 	@Override
-	public <D extends InstancedPart> Instancer<D> instancer(StructType<D> type, Model model, RenderStage stage) {
+	public <P extends InstancePart> Instancer<P> instancer(StructType<P> type, Model model, RenderStage stage) {
 		return drawManager.getInstancer(type, model, stage);
 	}
 
diff --git a/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/BlockEntityInstanceManager.java b/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/BlockEntityInstanceManager.java
index 254fd4358..e43961527 100644
--- a/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/BlockEntityInstanceManager.java
+++ b/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/BlockEntityInstanceManager.java
@@ -39,37 +39,6 @@ public class BlockEntityInstanceManager extends InstanceManager<BlockEntity> {
 		}
 	}
 
-	@Override
-	protected boolean canCreateInstance(BlockEntity blockEntity) {
-		if (blockEntity.isRemoved()) {
-			return false;
-		}
-
-		if (!InstancingControllerHelper.canInstance(blockEntity)) {
-			return false;
-		}
-
-		Level level = blockEntity.getLevel();
-
-		if (level == null) {
-			return false;
-		}
-
-		if (level.isEmptyBlock(blockEntity.getBlockPos())) {
-			return false;
-		}
-
-		if (BackendUtil.isFlywheelLevel(level)) {
-			BlockPos pos = blockEntity.getBlockPos();
-
-			BlockGetter existingChunk = level.getChunkForCollisions(pos.getX() >> 4, pos.getZ() >> 4);
-
-			return existingChunk != null;
-		}
-
-		return false;
-	}
-
 	private static class BlockEntityStorage extends One2OneStorage<BlockEntity> {
 		private final Long2ObjectMap<BlockEntityInstance<?>> posLookup = new Long2ObjectOpenHashMap<>();
 
@@ -77,6 +46,37 @@ public class BlockEntityInstanceManager extends InstanceManager<BlockEntity> {
 			super(engine);
 		}
 
+		@Override
+		public boolean willAccept(BlockEntity blockEntity) {
+			if (blockEntity.isRemoved()) {
+				return false;
+			}
+
+			if (!InstancingControllerHelper.canInstance(blockEntity)) {
+				return false;
+			}
+
+			Level level = blockEntity.getLevel();
+
+			if (level == null) {
+				return false;
+			}
+
+			if (level.isEmptyBlock(blockEntity.getBlockPos())) {
+				return false;
+			}
+
+			if (BackendUtil.isFlywheelLevel(level)) {
+				BlockPos pos = blockEntity.getBlockPos();
+
+				BlockGetter existingChunk = level.getChunkForCollisions(pos.getX() >> 4, pos.getZ() >> 4);
+
+				return existingChunk != null;
+			}
+
+			return false;
+		}
+
 		@Override
 		@Nullable
 		protected Instance createRaw(BlockEntity obj) {
diff --git a/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/EffectInstanceManager.java b/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/EffectInstanceManager.java
index 185e4edaa..c30187f05 100644
--- a/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/EffectInstanceManager.java
+++ b/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/EffectInstanceManager.java
@@ -21,11 +21,6 @@ public class EffectInstanceManager extends InstanceManager<Effect> {
 		return storage;
 	}
 
-	@Override
-	protected boolean canCreateInstance(Effect obj) {
-		return true;
-	}
-
 	private static class EffectStorage extends One2ManyStorage<Effect> {
 		public EffectStorage(Engine engine) {
 			super(engine);
@@ -35,5 +30,10 @@ public class EffectInstanceManager extends InstanceManager<Effect> {
 		protected Collection<? extends Instance> createRaw(Effect obj) {
 			return obj.createInstances(new InstanceContext(engine, engine.renderOrigin()));
 		}
+
+		@Override
+		public boolean willAccept(Effect obj) {
+			return true;
+		}
 	}
 }
diff --git a/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/EntityInstanceManager.java b/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/EntityInstanceManager.java
index 326527acd..b76c1966d 100644
--- a/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/EntityInstanceManager.java
+++ b/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/EntityInstanceManager.java
@@ -25,21 +25,6 @@ public class EntityInstanceManager extends InstanceManager<Entity> {
 		return storage;
 	}
 
-	@Override
-	protected boolean canCreateInstance(Entity entity) {
-		if (!entity.isAlive()) {
-			return false;
-		}
-
-		if (!InstancingControllerHelper.canInstance(entity)) {
-			return false;
-		}
-
-		Level level = entity.level;
-
-		return BackendUtil.isFlywheelLevel(level);
-	}
-
 	private static class EntityStorage extends One2OneStorage<Entity> {
 		public EntityStorage(Engine engine) {
 			super(engine);
@@ -55,5 +40,20 @@ public class EntityInstanceManager extends InstanceManager<Entity> {
 
 			return controller.createInstance(new InstanceContext(engine, engine.renderOrigin()), obj);
 		}
+
+		@Override
+		public boolean willAccept(Entity entity) {
+			if (!entity.isAlive()) {
+				return false;
+			}
+
+			if (!InstancingControllerHelper.canInstance(entity)) {
+				return false;
+			}
+
+			Level level = entity.level;
+
+			return BackendUtil.isFlywheelLevel(level);
+		}
 	}
 }
diff --git a/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/InstanceManager.java b/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/InstanceManager.java
index f164dfe43..e2976e4a8 100644
--- a/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/InstanceManager.java
+++ b/src/main/java/com/jozufozu/flywheel/impl/instancing/manager/InstanceManager.java
@@ -31,17 +31,6 @@ public abstract class InstanceManager<T> {
 
 	protected abstract Storage<T> getStorage();
 
-	/**
-	 * Is the given object currently capable of being instanced?
-	 *
-	 * <p>
-	 *     This won't be the case for block entities or entities that are outside of loaded chunks.
-	 * </p>
-	 *
-	 * @return true if the object is currently capable of being instanced.
-	 */
-	protected abstract boolean canCreateInstance(T obj);
-
 	protected DistanceUpdateLimiter createUpdateLimiter() {
 		if (FlwConfig.get().limitUpdates()) {
 			return new BandedPrimeLimiter();
@@ -60,7 +49,7 @@ public abstract class InstanceManager<T> {
 	}
 
 	public void add(T obj) {
-		if (!canCreateInstance(obj)) {
+		if (!getStorage().willAccept(obj)) {
 			return;
 		}
 
@@ -68,7 +57,7 @@ public abstract class InstanceManager<T> {
 	}
 
 	public void queueAdd(T obj) {
-		if (!canCreateInstance(obj)) {
+		if (!getStorage().willAccept(obj)) {
 			return;
 		}
 
@@ -89,7 +78,7 @@ public abstract class InstanceManager<T> {
 	 * @param obj the object to update.
 	 */
 	public void update(T obj) {
-		if (!canCreateInstance(obj)) {
+		if (!getStorage().willAccept(obj)) {
 			return;
 		}
 
@@ -97,7 +86,7 @@ public abstract class InstanceManager<T> {
 	}
 
 	public void queueUpdate(T obj) {
-		if (!canCreateInstance(obj)) {
+		if (!getStorage().willAccept(obj)) {
 			return;
 		}
 
diff --git a/src/main/java/com/jozufozu/flywheel/impl/instancing/storage/Storage.java b/src/main/java/com/jozufozu/flywheel/impl/instancing/storage/Storage.java
index 9052cb59b..78c3a474e 100644
--- a/src/main/java/com/jozufozu/flywheel/impl/instancing/storage/Storage.java
+++ b/src/main/java/com/jozufozu/flywheel/impl/instancing/storage/Storage.java
@@ -14,6 +14,13 @@ public interface Storage<T> {
 
 	List<DynamicInstance> getDynamicInstances();
 
+	/**
+	 * Is the given object currently capable of being added?
+	 *
+	 * @return true if the object is currently capable of being instanced.
+	 */
+	boolean willAccept(T obj);
+
 	void add(T obj);
 
 	void remove(T obj);
diff --git a/src/main/java/com/jozufozu/flywheel/lib/struct/AbstractInstancePart.java b/src/main/java/com/jozufozu/flywheel/lib/struct/AbstractInstancePart.java
new file mode 100644
index 000000000..71b55fc4d
--- /dev/null
+++ b/src/main/java/com/jozufozu/flywheel/lib/struct/AbstractInstancePart.java
@@ -0,0 +1,29 @@
+package com.jozufozu.flywheel.lib.struct;
+
+import com.jozufozu.flywheel.api.instancer.Handle;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
+import com.jozufozu.flywheel.api.struct.StructType;
+
+public abstract class AbstractInstancePart implements InstancePart {
+
+	public final StructType<?> type;
+	protected final Handle handle;
+
+	protected AbstractInstancePart(StructType<?> type, Handle handle) {
+		this.type = type;
+		this.handle = handle;
+	}
+
+	@Override
+	public StructType<?> type() {
+		return type;
+	}
+
+	public final void setChanged() {
+		handle.setChanged();
+	}
+
+	public final void delete() {
+		handle.setDeleted();
+	}
+}
diff --git a/src/main/java/com/jozufozu/flywheel/lib/struct/ColoredLitPart.java b/src/main/java/com/jozufozu/flywheel/lib/struct/ColoredLitPart.java
index 1b952ee9f..a6339f577 100644
--- a/src/main/java/com/jozufozu/flywheel/lib/struct/ColoredLitPart.java
+++ b/src/main/java/com/jozufozu/flywheel/lib/struct/ColoredLitPart.java
@@ -1,11 +1,11 @@
 package com.jozufozu.flywheel.lib.struct;
 
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.Handle;
 import com.jozufozu.flywheel.api.struct.StructType;
 
 import net.minecraft.client.renderer.LightTexture;
 
-public abstract class ColoredLitPart extends InstancedPart implements FlatLit<ColoredLitPart> {
+public abstract class ColoredLitPart extends AbstractInstancePart implements FlatLit<ColoredLitPart> {
 
 	public byte blockLight;
 	public byte skyLight;
@@ -15,21 +15,21 @@ public abstract class ColoredLitPart extends InstancedPart implements FlatLit<Co
 	public byte b = (byte) 0xFF;
 	public byte a = (byte) 0xFF;
 
-	public ColoredLitPart(StructType<?> type) {
-		super(type);
+	public ColoredLitPart(StructType<?> type, Handle handle) {
+		super(type, handle);
 	}
 
 	@Override
 	public ColoredLitPart setBlockLight(int blockLight) {
 		this.blockLight = (byte) blockLight;
-		markDirty();
+		setChanged();
 		return this;
 	}
 
 	@Override
 	public ColoredLitPart setSkyLight(int skyLight) {
 		this.skyLight = (byte) skyLight;
-		markDirty();
+		setChanged();
 		return this;
 	}
 
@@ -63,7 +63,7 @@ public abstract class ColoredLitPart extends InstancedPart implements FlatLit<Co
 		this.r = r;
 		this.g = g;
 		this.b = b;
-		markDirty();
+		setChanged();
 		return this;
 	}
 
@@ -72,7 +72,7 @@ public abstract class ColoredLitPart extends InstancedPart implements FlatLit<Co
 		this.g = g;
 		this.b = b;
 		this.a = a;
-		markDirty();
+		setChanged();
 		return this;
 	}
 }
diff --git a/src/main/java/com/jozufozu/flywheel/lib/struct/FlatLit.java b/src/main/java/com/jozufozu/flywheel/lib/struct/FlatLit.java
index cad1b8b85..19d95bcf5 100644
--- a/src/main/java/com/jozufozu/flywheel/lib/struct/FlatLit.java
+++ b/src/main/java/com/jozufozu/flywheel/lib/struct/FlatLit.java
@@ -1,40 +1,39 @@
 package com.jozufozu.flywheel.lib.struct;
 
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 
 import net.minecraft.core.BlockPos;
 import net.minecraft.world.level.BlockAndTintGetter;
 import net.minecraft.world.level.LightLayer;
 
 /**
- * An interface that implementors of {@link InstancedPart} should also implement
+ * An interface that implementors of {@link InstancePart} should also implement
  * if they wish to make use of Flywheel's provided light update methods.
  * <p>
  * This only covers flat lighting, smooth lighting is still TODO.
  *
- * @param <D> The name of the class that implements this interface.
+ * @param <P> The name of the class that implements this interface.
  */
-public interface FlatLit<D extends InstancedPart & FlatLit<D>> {
+public interface FlatLit<P extends InstancePart & FlatLit<P>> {
 	/**
 	 * @param blockLight An integer in the range [0, 15] representing the
 	 *                   amount of block light this instance should receive.
 	 * @return {@code this}
 	 */
-	D setBlockLight(int blockLight);
+	P setBlockLight(int blockLight);
 
 	/**
 	 * @param skyLight An integer in the range [0, 15] representing the
 	 *                 amount of sky light this instance should receive.
 	 * @return {@code this}
 	 */
-	D setSkyLight(int skyLight);
+	P setSkyLight(int skyLight);
 
-	default D setLight(int blockLight, int skyLight) {
-		return setBlockLight(blockLight)
-				.setSkyLight(skyLight);
+	default P setLight(int blockLight, int skyLight) {
+		return setBlockLight(blockLight).setSkyLight(skyLight);
 	}
 
-	default D updateLight(BlockAndTintGetter level, BlockPos pos) {
+	default P updateLight(BlockAndTintGetter level, BlockPos pos) {
 		return setLight(level.getBrightness(LightLayer.BLOCK, pos), level.getBrightness(LightLayer.SKY, pos));
 	}
 
diff --git a/src/main/java/com/jozufozu/flywheel/lib/struct/OrientedPart.java b/src/main/java/com/jozufozu/flywheel/lib/struct/OrientedPart.java
index c6559f92f..2f00ab4f2 100644
--- a/src/main/java/com/jozufozu/flywheel/lib/struct/OrientedPart.java
+++ b/src/main/java/com/jozufozu/flywheel/lib/struct/OrientedPart.java
@@ -1,5 +1,6 @@
 package com.jozufozu.flywheel.lib.struct;
 
+import com.jozufozu.flywheel.api.instancer.Handle;
 import com.mojang.math.Quaternion;
 import com.mojang.math.Vector3f;
 
@@ -18,8 +19,8 @@ public class OrientedPart extends ColoredLitPart {
 	public float qZ;
 	public float qW = 1;
 
-	public OrientedPart() {
-		super(StructTypes.ORIENTED);
+	public OrientedPart(Handle handle) {
+		super(StructTypes.ORIENTED, handle);
 	}
 
 	public OrientedPart setPosition(BlockPos pos) {
@@ -34,7 +35,7 @@ public class OrientedPart extends ColoredLitPart {
 		this.posX = x;
 		this.posY = y;
 		this.posZ = z;
-		markDirty();
+		setChanged();
 		return this;
 	}
 
@@ -42,7 +43,7 @@ public class OrientedPart extends ColoredLitPart {
 		this.posX += x;
 		this.posY += y;
 		this.posZ += z;
-		markDirty();
+		setChanged();
 		return this;
 	}
 
@@ -58,7 +59,7 @@ public class OrientedPart extends ColoredLitPart {
 		this.pivotX = x;
 		this.pivotY = y;
 		this.pivotZ = z;
-		markDirty();
+		setChanged();
 		return this;
 	}
 
@@ -71,7 +72,7 @@ public class OrientedPart extends ColoredLitPart {
 		this.qY = y;
 		this.qZ = z;
 		this.qW = w;
-		markDirty();
+		setChanged();
 		return this;
 	}
 
@@ -80,13 +81,13 @@ public class OrientedPart extends ColoredLitPart {
 		this.qY = 0;
 		this.qZ = 0;
 		this.qW = 1;
-		markDirty();
+		setChanged();
 		return this;
 	}
 
 	@Override
-	public OrientedPart copy() {
-		var out = new OrientedPart();
+	public OrientedPart copy(Handle handle) {
+		var out = new OrientedPart(handle);
 		out.posX = this.posX;
 		out.posY = this.posY;
 		out.posZ = this.posZ;
diff --git a/src/main/java/com/jozufozu/flywheel/lib/struct/OrientedType.java b/src/main/java/com/jozufozu/flywheel/lib/struct/OrientedType.java
index 1010220d6..6185819d6 100644
--- a/src/main/java/com/jozufozu/flywheel/lib/struct/OrientedType.java
+++ b/src/main/java/com/jozufozu/flywheel/lib/struct/OrientedType.java
@@ -1,5 +1,6 @@
 package com.jozufozu.flywheel.lib.struct;
 
+import com.jozufozu.flywheel.api.instancer.Handle;
 import com.jozufozu.flywheel.api.layout.BufferLayout;
 import com.jozufozu.flywheel.api.struct.StructType;
 import com.jozufozu.flywheel.api.struct.StructWriter;
@@ -24,8 +25,8 @@ public class OrientedType implements StructType<OrientedPart> {
 			.build();
 
 	@Override
-	public OrientedPart create() {
-		return new OrientedPart();
+	public OrientedPart create(Handle handle) {
+		return new OrientedPart(handle);
 	}
 
 	@Override
diff --git a/src/main/java/com/jozufozu/flywheel/lib/struct/TransformedPart.java b/src/main/java/com/jozufozu/flywheel/lib/struct/TransformedPart.java
index 195ad2da9..16a19233d 100644
--- a/src/main/java/com/jozufozu/flywheel/lib/struct/TransformedPart.java
+++ b/src/main/java/com/jozufozu/flywheel/lib/struct/TransformedPart.java
@@ -1,5 +1,6 @@
 package com.jozufozu.flywheel.lib.struct;
 
+import com.jozufozu.flywheel.api.instancer.Handle;
 import com.jozufozu.flywheel.lib.transform.Transform;
 import com.mojang.blaze3d.vertex.PoseStack;
 import com.mojang.math.Matrix3f;
@@ -15,15 +16,17 @@ public class TransformedPart extends ColoredLitPart implements Transform<Transfo
 	public final Matrix4f model = new Matrix4f();
 	public final Matrix3f normal = new Matrix3f();
 
-	public TransformedPart() {
-		super(StructTypes.TRANSFORMED);
+	public TransformedPart(Handle handle) {
+		super(StructTypes.TRANSFORMED, handle);
 	}
 
 	public TransformedPart setTransform(PoseStack stack) {
-		markDirty();
+		setChanged();
 
-		this.model.load(stack.last().pose());
-		this.normal.load(stack.last().normal());
+		this.model.load(stack.last()
+				.pose());
+		this.normal.load(stack.last()
+				.normal());
 		return this;
 	}
 
@@ -35,7 +38,7 @@ public class TransformedPart extends ColoredLitPart implements Transform<Transfo
 	 * </p>
 	 */
 	public TransformedPart setEmptyTransform() {
-		markDirty();
+		setChanged();
 
 		this.model.load(EMPTY_MATRIX_4f);
 		this.normal.load(EMPTY_MATRIX_3f);
@@ -43,7 +46,7 @@ public class TransformedPart extends ColoredLitPart implements Transform<Transfo
 	}
 
 	public TransformedPart loadIdentity() {
-		markDirty();
+		setChanged();
 
 		this.model.setIdentity();
 		this.normal.setIdentity();
@@ -52,7 +55,7 @@ public class TransformedPart extends ColoredLitPart implements Transform<Transfo
 
 	@Override
 	public TransformedPart multiply(Quaternion quaternion) {
-		markDirty();
+		setChanged();
 
 		model.multiply(quaternion);
 		normal.mul(quaternion);
@@ -61,7 +64,7 @@ public class TransformedPart extends ColoredLitPart implements Transform<Transfo
 
 	@Override
 	public TransformedPart scale(float pX, float pY, float pZ) {
-		markDirty();
+		setChanged();
 
 		model.multiply(Matrix4f.createScaleMatrix(pX, pY, pZ));
 		if (pX == pY && pY == pZ) {
@@ -83,7 +86,7 @@ public class TransformedPart extends ColoredLitPart implements Transform<Transfo
 
 	@Override
 	public TransformedPart translate(double x, double y, double z) {
-		markDirty();
+		setChanged();
 
 		model.multiplyWithTranslation((float) x, (float) y, (float) z);
 		return this;
@@ -102,8 +105,8 @@ public class TransformedPart extends ColoredLitPart implements Transform<Transfo
 	}
 
 	@Override
-	public TransformedPart copy() {
-		var out = new TransformedPart();
+	public TransformedPart copy(Handle handle) {
+		var out = new TransformedPart(handle);
 		out.model.load(this.model);
 		out.normal.load(this.normal);
 		out.r = this.r;
diff --git a/src/main/java/com/jozufozu/flywheel/lib/struct/TransformedType.java b/src/main/java/com/jozufozu/flywheel/lib/struct/TransformedType.java
index 6b59b3482..63c1c7cac 100644
--- a/src/main/java/com/jozufozu/flywheel/lib/struct/TransformedType.java
+++ b/src/main/java/com/jozufozu/flywheel/lib/struct/TransformedType.java
@@ -1,5 +1,6 @@
 package com.jozufozu.flywheel.lib.struct;
 
+import com.jozufozu.flywheel.api.instancer.Handle;
 import com.jozufozu.flywheel.api.layout.BufferLayout;
 import com.jozufozu.flywheel.api.struct.StructType;
 import com.jozufozu.flywheel.api.struct.StructWriter;
@@ -20,8 +21,8 @@ public class TransformedType implements StructType<TransformedPart> {
 			.build();
 
 	@Override
-	public TransformedPart create() {
-		return new TransformedPart();
+	public TransformedPart create(Handle handle) {
+		return new TransformedPart(handle);
 	}
 
 	@Override
diff --git a/src/main/java/com/jozufozu/flywheel/vanilla/BellInstance.java b/src/main/java/com/jozufozu/flywheel/vanilla/BellInstance.java
index 949cc71b4..971f24d1c 100644
--- a/src/main/java/com/jozufozu/flywheel/vanilla/BellInstance.java
+++ b/src/main/java/com/jozufozu/flywheel/vanilla/BellInstance.java
@@ -7,7 +7,7 @@ import org.jetbrains.annotations.NotNull;
 import com.jozufozu.flywheel.api.event.RenderStage;
 import com.jozufozu.flywheel.api.instance.DynamicInstance;
 import com.jozufozu.flywheel.api.instance.controller.InstanceContext;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.lib.instance.AbstractBlockEntityInstance;
 import com.jozufozu.flywheel.lib.material.Materials;
 import com.jozufozu.flywheel.lib.model.SimpleLazyModel;
@@ -68,7 +68,7 @@ public class BellInstance extends AbstractBlockEntityInstance<BellBlockEntity> i
 	}
 
 	@Override
-	public List<InstancedPart> getCrumblingParts() {
+	public List<InstancePart> getCrumblingParts() {
 		return List.of(bell);
 	}
 
diff --git a/src/main/java/com/jozufozu/flywheel/vanilla/ChestInstance.java b/src/main/java/com/jozufozu/flywheel/vanilla/ChestInstance.java
index 83fc3ad6c..4b95610ca 100644
--- a/src/main/java/com/jozufozu/flywheel/vanilla/ChestInstance.java
+++ b/src/main/java/com/jozufozu/flywheel/vanilla/ChestInstance.java
@@ -7,7 +7,7 @@ import java.util.function.BiFunction;
 import com.jozufozu.flywheel.api.event.RenderStage;
 import com.jozufozu.flywheel.api.instance.DynamicInstance;
 import com.jozufozu.flywheel.api.instance.controller.InstanceContext;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.lib.instance.AbstractBlockEntityInstance;
 import com.jozufozu.flywheel.lib.material.Materials;
 import com.jozufozu.flywheel.lib.model.SimpleLazyModel;
@@ -111,7 +111,7 @@ public class ChestInstance<T extends BlockEntity & LidBlockEntity> extends Abstr
 	}
 
 	@Override
-	public List<InstancedPart> getCrumblingParts() {
+	public List<InstancePart> getCrumblingParts() {
 		return List.of(body, lid);
 	}
 
diff --git a/src/main/java/com/jozufozu/flywheel/vanilla/ShulkerBoxInstance.java b/src/main/java/com/jozufozu/flywheel/vanilla/ShulkerBoxInstance.java
index 4b32d9c8e..3cee8063a 100644
--- a/src/main/java/com/jozufozu/flywheel/vanilla/ShulkerBoxInstance.java
+++ b/src/main/java/com/jozufozu/flywheel/vanilla/ShulkerBoxInstance.java
@@ -6,7 +6,7 @@ import java.util.function.Function;
 import com.jozufozu.flywheel.api.event.RenderStage;
 import com.jozufozu.flywheel.api.instance.DynamicInstance;
 import com.jozufozu.flywheel.api.instance.controller.InstanceContext;
-import com.jozufozu.flywheel.api.instancer.InstancedPart;
+import com.jozufozu.flywheel.api.instancer.InstancePart;
 import com.jozufozu.flywheel.lib.instance.AbstractBlockEntityInstance;
 import com.jozufozu.flywheel.lib.material.Materials;
 import com.jozufozu.flywheel.lib.model.SimpleLazyModel;
@@ -95,7 +95,7 @@ public class ShulkerBoxInstance extends AbstractBlockEntityInstance<ShulkerBoxBl
 	}
 
 	@Override
-	public List<InstancedPart> getCrumblingParts() {
+	public List<InstancePart> getCrumblingParts() {
 		return List.of(base, lid);
 	}