AVIF has >90% compat., especially for most-recent versions of browsers. JXL is waaay less supported, but can be enabled with config switches in both FF & Chrome (and it just works by default in Safari).

Again, inclusion of software-specific image formats like .AI and .XCF implies someone added those arbitrarily in Pawb/Lemmy code. Hoping that @Crashdoom et al. can chime in – if they’re not busy, obviously; AVIF compat. is a minor nitpick compared to the recent backend & downtime issues

List of compatible types is way more than that, according to the Windows-specific upload dialog – includes eyebrow-raisers like BMP, Windows Icon format, XCF (GIMP iirc), HEIC (x265 has a static image implementation?), Adobe Illustrator files, among others.

If none of those are an option on lemmy.world or other instances, guess that at least proves that Pawb’s fork of the Lemmy code can accept other formats.