Sch911, I think they'll let me have any necessary cooling upgrades.
I forgot some of the details since this idea has been stewing for a long time.
I imagine the tag axle would have 60 psi trailer tires smaller than the vehicle's regular tires and each would have its own fender. An air bag suspension would support the tongue weight and push the vehicle nose down. The tag axle would have the receiver hitch for the trailer on it and be attached to the tow vehicle by at least 2 receiver hitches, not normal ones but one under each frame rail.
As for the hack, I think time and corrosion will accomplish the same thing eventually. I had wacky electric issues with a Montana minivan including a speedometer that gradually re-adjusted itself while I drove in the rain.