Here’s a picture:
He has two extra buttons. I don’t know what one does (I am guessing a re-mapping of select for plinking), but the other is mapped to the up direction to let him do Akuma’s U2 in situations you may not otherwise be able to do it (someone else would have to confirm this), or ease execution there.
I don’t know if he used it at previous Evos because I didn’t see it.
I recall Full Schedule’s stick that had buttons mapped to two directions (up+back) may have been banned, although I am not sure it was ever reconsidered in light of future discussions:
It’s a bit questionable since it may allow things that were not intended (raw akuma u2s), and it duplicates inputs found elsewhere, but I guess if a person wanted 3 fierce punch buttons, it doesn’t sound so bad.
The rules do not clarify this. http://shoryuken.com/evo-player-guide/evo-additional-rules/
What is the official ruling here? One button + something else is bad, one button that is already mapped elsewhere is ok? So a stick could have the entire direction pad duplicated elsewhere? (up, down, left, right)