Duplicate Layers with sequential numbering rather than "copy"
When you duplicate a layer it would be much better if, rather than the XXXX copy suffix the duplicate layer was numbered. And preferably numbered XXX_0001 (or a format one could specify in the Preferences). This would make working with layers much much easier - especially when working with After Effects.
Not an exact match for the custom numbering, but why not replicate what Photoshop does in Panel Options. The last checkbox in the dialog:
--- Add "copy" to Copied Layers and Groups ---
Uncheck that and it duplicates the layers and groups without the undesired "copy"