Blender not supporting animation export in separate file?

I brought this up in a separate thread, but thought it warranted it’s own. Basically, I rigged a skeletal mesh in one .blend file and then created another .blend file with original mesh linked as a proxy so I could create an animation. When I try to import into Unreal, it looks like Blender is monkeying with bone names, cause they all have “_0” appended according to the error:

Here’s my scene with the linked mesh. You can see the bone don’t have “_0” on the end of them.

Anyone else hit this?