Looking beyond this election, this is EXCELLENT.
The perfect debate would have no moderator whatsoever. Just a timer — candidates choose their own topics.
The happy medium achieved here is that a politician need not endure a moderator he/she mistrusts.
Trump’s courage advances civilization once again.
I'd add that, there's a timer minimum, after which the first game-show-style button press (like in Family Feud) turns on the microphone of the candidate who wishes to respond and the first microphone turns off. When the debate is over (2 hours is about all one could stand) everyone would be able to see how much time in seconds each participant used, and the audience reaction (decibels and duration) would rate their performance. Best performance in the least time would probably be the winner.