Obviously you have both been out of the loop, since the latest model is the Prodigiously X2.
The idea is to have a separate brake controller for each wheel so that the
brakes can be used for stability control (as in the Acura RL). The X2 model DOES require either two long extension cords, or one 220v cord. The primary purpose is to allow the operator to separately control the
brakes when and if sway occurs. There is, unfortunately, a lengthy training program necessary, since clumsy actuation would quickly get your trailer headed into the adjoining county.
I understand that an X4 model is in the works. Doesn't Frederick's
Fiberstream have tandem axles? This would no doubt give him the ultimate in control, and isn't that what we all want?