Campers fully usable off truck without additional supports?

Arctic Fox 990 is fine, but the only caveate is not to fill the water tank up if OFF the truck with out support. Apparently the bladder will buckle the bottom or something like that.

I've had it off a few times, lowered to a few inches off the ground, works/feels fine...

It does get a little 'iffy' when I have to load in the wind, as in "Yikes, what was I thinking...." so it's a quick load if windy if I have too...

Hope that helps...