If you and whoever else may be up there are smaller, I don't see why it would not work. You could always build a prototype cheaply and put weight on it to see how it would work before committing.
Personally, for a savings of 20lbs., I would stick with the safety margin of 3/4"...maybe just remove the carpet. I doubt there would be a sudden, catastrophic failure but why risk it if you were on a trip?
2005 Chevy 1500 AWD
4x4 conversion, Ultralight RB50 floorplan,
Firestone Destination A/T, Silverado wheels, 3000w inverter, PIAA lighting