..Mar-K documented this suggestion, but I have to find someone that actually did this...
After seeing the pictures and full writeup I think it's best to leave it as a "suggestion" for sure not a strong one, and hope that no one actually attempts it.
Still doesn't look/sound like a good idea to me.
The simple option is to trim holes in the bed wood for the frame to protrude through, and cover it with some nicely curved and fabricated heavy sheet metal covers, not unlike a wheel tub just a lot smaller. Looks like about 1.5" tall above the bed floor is all that's necessary, and I'm guessing 8-10" long, and a tad wider than the frame member, so 3-4" would be plenty.
Depends on your intended use for the truck. I might have problems with it because I use trucks for what they are, and a non level floor while not a huge problem would bother me. But the number of trucks I see at shows that apparently are never used is supprising... Many of them could get away with such a modification to the bed floor.
What are your thoughts?