I think we definitely need somewhere to document the image formats.
Preferably both a custom page on the doxygen area and a thread here.
(Evidently I don’t know enough about the formats to contribute.)
Now that you’ve pointed out that link I do vaguely remember that discussion. So much has happened since then that it completely slipped my mind.
I very nearly suggested this in my last comment but decided not to mention it since I knew you were the img2pok author and you hadn’t been in the conversation until now. (And I was in a rush.)
A warning on pok2img would be an excellent idea since I suspect many people won’t stop to read the documentation, but they might stop if the image encoder tells them about the possible problems.