This still could be interesting for the Pause button, to display a menu, to launch a mega-bomb that destroys everything on screen, etc, etc. It's interesting because it's very simple to implement.
I have given some thought about it, but tell me, how many msx users have those FM-Towns controllers?
I think MSX users that use FM-Towns controller are rare even in Japan. Actually I have only a MSX joypad but I need a second joypad. I'll probably buy one soon.