Hi, thank you !
1. The animations should be tagged when exporting to aseprite format (yes I checked it's well tagged on my side). Ok to have all animations in one spritesheet, noted for a future update.
2. Effectively, if there are new animations or deleted animations it will not update pixelover project animation from the gltf one. I'll find a way to do that in a future update, thank you for the feedback !