I don't think this is a bug per-se but more like an oversight so I'll post it here, if I'm wrong a mod can move the thread to the right place!
When you reload sprite frames from a source it doesn't update any duplicates of that frame in the animation and you can't update them individually since the option to reload is greyed out for any duplicates for some reason. This makes you delete any duplicate frames and re-import and rearrange them. It's not a game breaking issue but it is noticable when doing lots of tweaking with animation frames and such.
Is it possible that in future updates you can either reload every duplicate individually or that when you reload a frame, every other duplicates gets updated as well?