Gentlemen, if I may. Valid playfield exploit is not strategy. It is passive play. The ball is in motion, yes, and you may do it as normal modes of playing. But doing it constantly for any extended period of time is passive play. A TD has every right to expose rules and to sanction this in my book. That goes for short plunge back to shooter stuff like on White Water as well.
“This is passive play. I will grant you three more attempts at this. Then you must full plunge and start your ball or you will be marked zero points for the game.”
The valid playfield - or start-of-ball event - is not game design.
Unless someone can do me wrong, it is made to ensure players on location not feeling being robbed from their ball in play on an unstable game. Nagging the staff for a refund or vandalising the game.
When the norm for this was changed from 1 to 3 switch transistions out of trough/shooter lane, it was poison for expert play and competition usage. Let alone when resetting the counter upon a ball returning to trough.
I wish the norm is and always had been to keeps it classic first switch and go, when games are set for competition.