Tom, it's not a stupid idea. I myself am considering making something not dissimilar, because my tops are so big that I darent pole them from my
( small) subs. I have been thinking of making some form of folding stand to elevate them safely. I reckon you need something similar, only smaller.
Tony( A1) You're correct of course, but if he's using a twin 15" cab I think he might have enough bass, even though he could have more with them on the floor.
Theo, how right you are was brought home to me when I forgot my speaker stands, and placed my cabs on the floor. Even though they were only my normal top cabs, the increased bass response was amazing.