Hacking Gecko OS code for switching button actions? (Metroid Prime Trilogy)

[Nintendo Maniac]

I'm looking for a way, preferably through a Gecko OS code, to swap the actions of A (shoot) and B (jump) in Metroid Prime Trilogy's multiplayer. Turns out there's no option for it in multiplayer, only for single player (what gives?).

I know it's possible since there's that "Hold Z To Aim, A To Run, Press B To Shoot" code for RE4:Wii (US)