It's a fair point that obstructing draft legislation is a kind of de facto prohibiting of votes, even if crown consent does not enable stopping a vote directly. But in practice I don’t think consent could possibly be used this way without the tacit approval of the government (like with the prorogation of parliament case). I brought up parliamentary sovereignty above precisely because of this. If parliament is sovereign then ultimately the limits of crown consent are for parliament to decide. So the crown does not truly have a binding veto, if that veto can be removed or undone by parliament.
That said, it would be very interesting if such a veto was attempted and it went to court, we’d get to see more constitutional clarification in action!