The "last second" icing is what really irritates me. And it's probably less effective. You've now given the snapper, holder and kicker a practice kick.
Plus you look like a total moron when they miss the first one and make the second one.
I don't have a problem with the old-fashioned version to make the kicker think about it for a few more minutes. That's similar to icing a free throw shooter, which is done all the time.