It may be beyond the scope of Retroarch, but on the Playstation Classic, it would be nice to have a file manager or the ability to delete savestates, etc. But I believe I read an opinion somewhere, possibly of Libretro’s, that it would be dangerous to implement. I agree to a point.
This may be the greater of evils, but I’ll share some workarounds. Windows 3.1 works well in DOSBox-SVN, and with a .bat file in /media, or only as deep as you wish to expose, you can access access these files. I also like DOS Navigator.
Do note though that DOSBox-SVN doesn’t seem to expose Long File Names (LFNs), so no utility will let you see past 8.3 filename conventions. So if you copy a file, it will be in 8.3 format (such as, rom Summon Night Swordcraft Story 3.gba may become SUMMON~1.GBA, not safe to assume it’s not the 1st or 2nd game in your roms or save folders). But modifying and moving files seems to preserve the original filename. I don’t recommend moving or modifying important files, such as Retroarch files, but it’s nice to be able to read and edit txt files. I like to text dump game guides, copy the file, and backspace stuff from the copy when I’ve passed that point.
Here’s some other use cases I have: For the many incomplete & buggy translations of Summon Night Swordcraft Story 3, I have 2 roms: SNSS3E.GBA and SNSS3J.GBA (patched and original). I often have to jump between them to get past a crash and further test, so 2 bat files in the saves folder help do just that. As simple SNSS3EJ.BAT doing ‘copy/Y SNSS3E.srm SNSS3J.srm’ and vice versa.
I’m also currently creating a custom playlist for such fun utilities. But due to DOS 8.3 filenames being in all caps and Linux being case-sensitive, I can’t simply copy my preferred icons in Assets to make it custom playlist icons work. TOOLS.LPL will look for TOOLS.png and TOOLS_content.png, etc.