Since pixel editing tools aren't a major focus of the project it would make a lot of sense to allow better integration with an editor for easy imports and faster setup time.
If you could make PixelOver able to import/export .ase and .psd files, that would be amazing :)
Right now there are lots of Aseprite users which also use Photoshop (or similar software that can use psd files) struggling with their workflows due to the current impossibility to convert from/to these two filetypes.
Just in case it helps :)
.ASE file format:
https://github.com/aseprite/aseprite/blob/main/docs/ase-file-specs.md
.PSD file format:
https://www.fileformat.info/format/psd/egff.htm
https://github.com/layervault/psd.rb/wiki/Anatomy-of-a-PSD-File
https://www.adobe.com/devnet-apps/photoshop/fileformatashtml/