If it is a problem they could start by saying it's become a problem and just asking people not to next year? Most of the people doing it don't actually want to hurt yt.

And a couple time previously they've had to change the noms, offers, or requests max/min numbers, I suspect a minor rumbling about that possibility would also be motivational.

People would wank furiously either way, of course, it would have to be causing worse problems than a few lingering iphs, but if it trends up it might.