Track rail mounted sleep platforms?

Putting in a full width sleep platform at the exact height of the bed track rails to give clearance underneath for a cooler and bins. Anyone done this?
I'll be using a standard topper, which leaves 20" of head space. With my 2" mattress the remaining 18" overhead is the same as a USN submariners quarters...livable enough but crawling out will be trickier.
I'm thinking of using track clamps (pic) to mount aluminum 90 angle sides/front to hang three sections of 3/4" ply, with a single vertical plywood support up the middle (reinforced up top for hinges on the three platform sections to gull wing up from the side access windows) Simple and light.