Yeah, I like this. Otherwise, if a team is trying to make a long game-winning drive, the defense can just PI and limit the offense to 15 yards per play.
Yet somehow this had never been an issue at the college level.
I do not like the spot foul because you automatically assume the play would be executed otherwise. Receivers drop balls and passes are inaccurate all the time. It needs to be just like in college. 15 yard penalty and no more.