That would be a discretionary nightmare, for refs, players and
fans alike. Yesterday ref had discretion on whether to say ball played hand or hand played ball. He chose the latter and if so, that is worthy of PK every time. Friday night, simple, don't commit a foul in the box if goal likelihood is low. Other problem is where do you set the wall? Do you allow a wall. Or do you get a pic like chance from where the foul occurred?
Basically, refs already have discretion not to call ticky tack fouls in the box.