Well, I don't see any night wings doing this. And staff in the neutral game, this allows a true 50-50. Fg Cross up gives you awesome opportunity to add quick extra damage without changing the neutral game. If they blocked the wrong way or wake up you can get a punish. If they hold down, I can do 1f2 1f2 1f2 until they don't.
If this is known, are people not using it because it's not practical? I was using this online last night and had pretty decent success with it. It's not my go to solution, but it is a great way to catch you offguard while remaining safe.
Also, isn't everyone always bitching about not being able to cross up wake ups mid screen? This seems pretty reliable to me.