That could be fun.
I'd kind of like to see a 'game show' style score counter above each candidate. Each time they tell a verifiable lie, it goes "DING" and the number goes up.
If the town halls from a couple weeks ago are any indication, Trump will have much more difficulty than Biden handling questions where the answer makes him look anything but 'perfect'.
Also, while it won't actually happen, I'd like to see Biden call out Trump every time he speaks out of turn or goes over. Something along the lines of "Did you forget the rules already, or do you think you don't have to follow them any more than you think you have to follow any other rules?"