I hereby propose the "Kindergarten Format for future presidential debates:
Put plexiglass shields around the candidates podiums, big enough to allow hand waving. candidate mics are normally off. Tell the candidates this is for COVID reasons. Give the moderator 2 big buttons which turn each candidate mic on for, say, 2 minutes. Candidate podiums will have 2 lights, one green and one yellow. Moderator asks a question, and presses the appropriate button. Candidate green light goes on and mic goes live. After 90 seconds, the light goes yellow. After 2 minutes, light goes out and mic goes off. The podium shielding will muffle any overtime shouting and the debate takes on an aura of adult participation. If this seems draconian, have the first debate as usual, with the threat that if it degenerates, the next 2 will happen under the "kindergarten rules".