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/