I’m still talking about the difficult plays to see when the runner is down. This was suggested as a potential fix for a play like the failed THill sneak. A dude lowers his head into a pile of guys and has even more pushing from behind. That view for almost any ref is likely obstructed for the most part making it difficult on when to blow the whistle. That part you added is also key though for post tackle movement of the ball. All those times guys get tackled and place the ball as far forward as they can would pretty much become irrelevant. I think the other piece to this is the amount of time to practically implement this into the game. Are the refs going to check an electronic screen every single down to ensure the ball is placed correctly? Any given play can turn into a tough call for placement.