Please test the release candidate of Blender 4.4! Especially with the transition to Slotted Actions, see if your old animations are still good when you load them. Give it a good shake, do weird stuff.
Grab the RC: https://builder.blender.org/download/daily/
Docs about slotted actions: https://developer.blender.org/docs/release_notes/4.4/animation_rigging/
@sybren Does this handle linked animations from other blender files?
@Feral3D of course!
@sybren I should have assumed you clever cats thought of everything. n______,n
but also.... if that is true, why am I still debugging