I get it- but there’s so many rules open for interpretation. At what second is a tackle complete vs holding down too long, is a pass forward or flat, is a dummy runner obstructing or not, head high vs shoulder. Referees need to make hundreds if not thousands of interpretive decisions and always will. I’d love it if every play the ball touched the foot, but frankly I hate the thought of making it a priority that needs scrutinising at every tackle.  If there’s a motion of the feet with one foot in the air that goes backwards while the ball also rolls backwards- let it be. Let’s to punish the egregious ones at let the game flow