Please natively support export (and maybe import) to OCA (Open Cel Animation) format.
Operating System:
Any of them
Description of the feature
OCA is a newer format that's designed for seamless usage of traditional 2D cel animation between any art or animation program that supports it. It's meant to be simple and already there are exporters and importers being developed for krita, blender, and it's natively built into OpenToonz/Tahoma2D. I know for a fact that GIMP in later releases plans on supporting animation features built into it from the GIMP Animation Package (GAP) program. So it would be an excellent opportunity to be able to do some animation in GIMP and then open the very same project in say natron or blender, even ones like After Effects or any program you desire should a plugin be made for it.
Use cases
Because GIMP is planning on later releases to expand animation capabilities, it makes sense to be able to export or import OCA projects just like how you can export ORA files.