I will be interested if any more info on this turns up. One of my next projects is getting the spare out of the bed (and from under the toolbox) and back where it belongs. I really don't want the spare as thief bait every time I park somewhere.
One thing about all this... it is a SPARE... its job is to get you home in case of a failure so it could be a smaller tire that would fit under the bed. The only downside to having it be a smaller size is that it prevents using it in a normal tire rotation and thus exercising the spare tire winch when the tires are rotated. Like every other mechanical device the spare lift needs to be occasionally maintained.