Don't want to get too far off track from the frame thread and will start a build thread if the customer wants. Simple version is composite panels will be bonded and bolted together with some internal panel structure. There will not be a tube frame or "studs" like you would have in a house. The idea is to make the box "monolithic". Think of a one cubic foot box made from thin sheet metal. It cannot rack or deform, even though the material is relatively thin, as the sheet steel attached to each piece prevents movement of the other pieces. Kind of like trying to crush an egg shell vertically in your hand. Even though the shell is thin, you can't do it.
Isulation will come from several sources, reflecting heat, i.e. preventing it from entering the living space, as well as keeping heated or cooled air inside that space. Second, will be well sealed joints and seams to prevent drafts or air intrusion. Third is to minimise window and door openings, no pop up tops, tent fabrics, screens, etc. Fourth is a plastic based foam with R-7 per inch and a special coating to tie everything together. R value could actually be in the 30's if it all works well together and acts according to our testing, but we will see.
Back to the frame flex: In the trail sloping to the right example, as given above -- your left front tire could lift as you transition from sloping ground to more level ground. This is quite common in off-roading. I have experienced it in everything from a Land Rover LR4 (almost zero articulation) to a classic Steyr-Puch Pinzgauer, again, very little articulation.
Contrast that with a trophy truck or class one buggy, both of which have HUGE suspenion travel and are relatively heavy for their size (about 6,000 pounds) The body stays level as the truck races through the desert and the suspension allows the tires to follow the terrain underneath. They are full tube chassis, so I can assure you there is little if any twist or flex. Though the wheel travel is considerably less, a race car is designed the same way: stiff chassis, fantastic suspension setup.
A more down to earth example is something like this - Toyota truck has little to no frame flex or twist. When traveling difficult terrain, the tires follow that terrain and the body remains relatively level. A truck body or camper box flopping around causes the vehicle to shift or slide and reminds me of driving a truck with a half full water tank in the bed. The water "pushes" you or "pulls" you as it sloshes around in the tank, even though the tank is strapped to the bed (assuming no baffles)
body is relatively level and though there may be less weight on one tire than others, the lockers, which every off road vehicle should have, will do their job and pull you through. Now, if you have some soccer mom AWD open t-case, traction control, open diff mall crawler and lose traction on one tire, thereby ceasing forward progress, then you are on your own.
EDIT: a tippy or tipsy vehicle is difficult to control and unstable. So, if it came down to having a frame that twisted or having a rigid tippy vehicle with no articulation, I would prefer the former.
