Those are for maintenance and are never intended for navigation.
I'm sorry, but that doesn't make sense. If the keyboard is there, if the arcade machine is in your home, why in the world wouldn't you use it?
I have thousands of roms to choose from. My buddy will say, "Let's play Track and Field next". I slide out the keyboard just enough to hit "tr" and the game is highlighted. It's that easy! I mean, yeah, you could scroll or page down with the joystick, but with this keyboard feature, I'll be playing before you even find it.