Originally Posted by Laco
I can't believe that Ford didn't design the transmission so you can't damage the engine. Every other manufacture does.
That part is easy -- Ford could just upshift transmission to drop engine RPMs. Unfortunately, that also reduces engine braking which leads to faster vehicle speed; exactly what you don't want. For now it's up to driver to slow down enough using brakes to allow a downshift so engine can do more good.
By the way, most manufacturers don't have to deal with extreme weight of a motorhome -- engine braking is very different when only slowing a 3,000-pound car. Most cars have much higher engine-size/weight ratio.
Fortunately there will be solutions to all this before too long.