Sure, any emulator that can be ported to the RG99 is welcome - as already mentioned, lack of working emulators is the biggest problem at the moment. SNES would also be nice to try (no chance of full speed I'm very sure, but a lot of JRPGs do not need full speed), perhaps even PSX (again, 2D turn based stuff would probably be playable). MAME as well, some games seemed quite playable on the original fw, so should definitely be at least somewhat usable under OD. And, of course, NES, we have that one-off discord build of FCEUX, but it's slow for some reason, maybe it will be faster if you try to build it from Gameblabla's source.
We'll take whatever we can get - again, thanks for looking into this.