Sounds like a great idea. But do you really think the crooked debate coordinators would ever agree to this? ;)
But something clearly has to change. If there's no other recourse, then conservatives should just boycott debates.
In general, though, I would say that debates rarely favor the cause of truth. Why? Because we should, as Mark Twain said, "Never argue with stupid people. They will bring you down to their level and then beat you with experience."
Debating/arguing with liberals is definitely arguing with "stupid" people. It's like casting pearls before swine, and Christ warned against that.
The proposal I suggested would not be a strict debate - more like a light version of a trial, where both candidates would be grilled by the best that the other has to offer. Also both candidates would be offered by their chosen interrogator the opportunity to present their strengths.