This particular truck has a sprayed-on bedliner; and I DO have a rubber mat :-)
I think the squat has a lot to do with the spring suspension, even as a 4 x 4 with a "camper package"?? (It has a lush, limo-like ride as a daily driver) Ed bought me a really rough Ram 1500 to use just as a "rolling camper cart" - and THAT ancient old thing doesn't squat very much under the camper. But it has leaf springs. We brought the camper home with an F-250, and of course that didn't squat at all.
I'll get the tiedowns installed this week, re-load the camper; and we'll go for a ride to the Cat Scales.
Ironically, with the truck squatting this badly - the camper is perfectly level?!