Modding Gamecube Triggers

[Northern]

Hey guys, so I just have a quick question about modding gamecube triggers. So my biggest annoyance with the gamecube controller is that the L and R button are not automatic like all other buttons are and so because of this I sometimes miss a perfect shield because of the delay in my L button so I'd like to know if modding the L and R buttons on a gamecube controller would be legal not just for a local or regional but even for a tournament as big as EVO. I'm pretty sure I remember a video of AnTi in February showing off his new gamecube controller with modded L and R buttons to where those buttons acted just like all other buttons and then he went on to win I think ETSU Con the next day, I'm not sure if he still uses that controller or not

TL;DR: Is modding the controller to make the shoulder buttons act like all other buttons legal at the highest level of Smash