Entirely agree in theory that there are hands that must exist where partner opens 1NT and you want to know how many aces in order to bid the slam. In reality I have never seen one (any hand that strong, you usually have 3 of the aces yourself, so you can just bid a small slam anyway).

In any other situation Gerber is madness and even more likely to be confused, particularly if the suit/NT hasn't been definitively agreed, or clubs have already been bid. I've even found pairs that play *any* bid of 4C anywhere, in *any* situation as Gerber. Rather them than me, frankly.