Saw two different truck campers at the state park we were at just this last week end. One was off the truck, standing alone, and family of 4 using it at the campsite.
Second one was strapped to a utility trailer, resting on the floor of the trailer, unhitched from the truck. Another family of 4 using it.
I would think, with any truck, regardless of size, you could lower the jacks to suspend the truck camper over the bed of the truck, or even just enough to reduce the weight in the bed of the truck, or perhaps to level the truck camper without removing it completely from the bed of the truck.
I don't think the OP was asking for a debate on "is this acceptable or permissible in my Home-owner-association community?". Rather, can it be done, ... say for example ... "at home" ... the answer is yes. I see it quite often at Indiana state parks where truck and truck camper have separated.