I would assume that your increase in fold equity would have to be equal to or greater than your lost pot odds for it to be a mathematically correct play.

If you know your opp will fold to your large bet 50% of the time, and your draw will hit 30% of the times that he calls, then you are going to win the pot ~65% of the time. You can now bet 65% of the pot and still have it be a winning play in the long term, I think. all of this assumes that you are correct in your guess of your fold equity, and that a 65% of the pot bet will be big enough to make your opp fold without an actual hand.

I dont know if this is even remotely right though, so dont go away from this thinking that it is.