Before attending Mac's seminar and only getting bits and pieces of it second hand, I was very skeptical of what he had to say. But after meeting and listening to him, his idea of the being able to use the exit window is so that when all else fails, you still have an out. His first line of defense is to have good quality RV certified smoke detectors in the bedroom AND rear of the coach. Check the operation of your CO detector, too. The placement of fire extinguishers in the bedroom and kitchen (his are actually better) may give you the momentary fire suppression you need so that you can get to the exit DOOR. Being able to properly use an extinguisher is probably as important as having an escape plan.
In regards to falling to the ground, Mac suggests putting the picnic table under the window when you set up. Or prop your step ladder there. He had some preliminary information on an escape ladder that mounts under the overhang and extends. Unfortunately, the design is not quite right for BH's. They're supposedly looking at a folding step to mount to the wall to accommodate the design.
Personally, I went for the two smoke detectors and the fire extinguishers. One in the bedroom, the other at the door mounted over the OEM dry chem one. In most instances, victims are dead from smoke inhalation long before the flames touch them.