I could see a chess clock or something similar being the “moderator”, just to keep things on point and moving, and helping to avoid each talking over the other.
Precisely what I think.IMHO conservatives should promote that approach for all elections. Candidates should put their debates online, whether or not the TV covers live.
And there should be no limitation on what visual aids are used by the participants - provided only that all data be properly sourced, and made available to the opposition at least a day in advance.