This isn't going to affect Shai very often, btw, beyond how often POE falls off past the first two months.
He's the best I've ever seen at using his upper shoulder to push off while keeping his forearm loose so he doesn't extend. He uses a shrug, which the video talks about as legal.
NBA refs will have a new emphasis on off-arm push-offs by offensive players for the 2026-2027 season.