There's not much games for that system though, even in Japan. And seriously there was nothing really "good" for it, as far as I can remember in the shelves of the retro shops.
It does seem as if the lauchers don't use the -force-module argument, so each launcher can in fact be used to launch any type of supported image. It's worth trying a PC-FX rom image if you've got one and want to play it - it doesn't seem to matter much which front end you pick at present (it just maintains a different default folder for each launcher, I think).