One thing we are all forgetting, is that the figure was not an actor was a stunt double, so the size of the character or how the character may be dress, means nothing, bc when they decide to say who is it, if is EQ, Rumple, Jafar, Aladdin, or any other person, they will not be thinking, oh, cant be them, bc they are all to small, nope, they would not even remenber that part and if they are asked, they will probably say that was a simple vision, so not the real thing.
crack theory, maybe is prince Neal from the future, lol i mean we have RB baby from the future that is actually a god that exists since forever, so prince Neal being Emma nemesis, would be almost normal, of course Future henry also works like @TheWatcher said.