MISSION ACCOMPLISHED.
I hired the man that took it to the scale for the trip to the Krasl Concours, in St. Joseph, MI. I thought he told me that his Avalanche was a 3/4-ton. While we hooked it up I asked again he told me it was a half-ton. That made me very nervous. Anxious, in fact.
However, he was confident that the drive across the state of Michigan would be a breeze since it's virtually flat. In fact, he said it was a breeze. He said his gas engined truck never even breathed hard towing a 12,000 lb. load.
He had never towed with a weight-equalizing hitch before. He was amazed at the stability and the noticible feeling of weight transfer to the front wheels. The attitude of the truck changes noticible.
I learned a great lesson about weight equalizing hitches. Too little torsion will allow the porpoising that I experienced just before I crashed. It allowed the trailer to get to an angle where the friction left as the equalizing arm unloaded and it fell out of it's socket. That, coupled with the fact that I loaded the Porsche (rear engined) too close to the rear created a cascade failure that was impossible to overcome.
The conclusion, after it's first long run, is that the aerodynamic shape, coupled with a full belly pan and rock-hard tires (offset by air ride) on precision packaged bearing hubs makes this trailer much easier to tow than the norm. He also loved the brakes. He felt that the trailer's brakes were doing all the work.
I'm relieved that there's nothing wrong with the design of the trailer and I can now go on to the next 2 projects.