I think as long as you have a
stable foundation under each jack you will be fine. My AF 990 sits outside year round sometimes on the truck & sometimes off, although mine is on cement. I never put anything under the corners of the camper to support it, I let the jacks do the work, been doing that on my two campers for 14 years & never had a problem.
Big Rig
04.5 Dodge Quad,3500,CTD,DRW,4X2,48RE, Ranchos, Tatman Wedgies
2015 Arctic Fox 990, 100W solar, power rear awning, Fox Landing, no generator, no oven