I was also getting menu corruption in the old oswan in Makai Toushi SaGa on the PAPKIII.
oswan is still very good. I didn't ever hear of guilty gears, so I didn't try it. The more recent Oswan works ok enough for me with the English translations patches of Makai Toushi SaGa, FF 1 and 2. It even looks half-decent fullscreen, I guess since WS also had a rectangular screen. Unless more RPGs are translated, I might not ever play any more WS games. Romhacking only has 14 translations for WS. I just don't know enough Japanese to figure out what is going on in many WS games.
Can mednafen work fast enough? Can it do bilinear filtering? I remember playing with it on Pandora, but it seemed to have all kinds of problems assigning keys and randomly crashing...but that was a long time ago.
Why does the sound volume always revert to a TOO LOUD setting, even after you set volume to 0? Setting volume=0 in Settings usually lasts until after I run one program, then the gmenu restarts(?) and volume goes back to 60. The brightness setting sticks. Can I do something to make sound volume stick?
Volume control works in Gameblabla's Useless firmware for K3S. (What is K3S?) If it is some easy little thing like putting cat 20 > /dev/mixer in some script someplace or some change to gmenu can you tell me the secret?
What keys are the Volume - + buttons? I don't really want to use them to play with volume, but might want to reassign them if I try to port games that need more buttons. Nethack might be fun with the big screen.