Local instance overrides

I'd like to instance over a collection or object to another scene and make a local override. This is useful for animation and keeping files organized, as it is right now I need to make a separate animation file in order to use the instance override.

Generally when I animate, I prefer making sure that the core rig data isn't editable so that there aren't different kinds of rig versions floating around. It's fairly standard practice in animation studios as well.

I'd like to see local scenes be able to do this, so for small projects I don't need to make multiple animation files or I can do animation tests within one file and keep things nicely organized.