To achieve a "true" duplication of layers or compositions in After Effects—where changes to the copy don't affect the original—you need to ensure the underlying source assets and nested hierarchies are also duplicated and re-linked. The "True" Duplication Method A standard (Windows) or
Alt-drag (Windows) or Option-drag (Mac) the new source from the Project Panel onto the layer in your timeline to swap them. Handle Nested Comps true layer duplicator exclusive
The term Exclusive signifies that this duplicator bypasses the host application’s standard memory management for layers. Instead of creating a shallow copy (which references original pixel data until edited), it performs a of the layer’s object graph. This prevents unintended "spooky action at a distance"—where editing one layer inadvertently alters its duplicate due to shared resource handles. To achieve a "true" duplication of layers or