i personally disagree with the idea of sharing your set with the opponent
so i'm not going to say that it should be required unless it's something that mostly if not everyone else wants
since i personally don't even use customs
But the surprise wears off once you spring it on them. Getting one surprise special off isn't going to change the course of a match most likely.
IDK. Maybe the opponent should be made aware of custom move changes
when are you buying a wii u o my god