Well, lock-on, Shotlock, and lock-on switch can still be assigned to two of the shoulder buttons, just like how it was in PSP BbS. The remaining two unused buttons can then be used to cycle up and down through the commands.That would be a great idea to do but at least two of those shoulder buttons will have to be taken up with lock on and shotlock.
Actually, though, I liked how we could cycle through the command menu in PS2 KH2 (or was it KH1?) with the right analog stick while holding one of the shoulder buttons. It was really convenient.