From what I have seen, the materials used in RVs aren't the problem, it's the assembly.
I would use a lot of jigs and fixtures to ensure repeatable, accurate alignment of components when they are put together. Then you would need to control exactly where the fasteners are put so each unit is assembled identically (or at least pretty close). Right now, the guy the staple gun is looking at a rough area where the staples need to go and shooting away. Some people will get RVs where 80% of the staples go into proper supports (which are hidden inside walls, etc so you can't actually see them) and some people will get RVs where 20% of the staples go into proper supports. Guess which RV will fall apart first? the solution could be as simple as having the manufacturer of the part put a peelable label that shows where fasteners should go. After the worker puts the fastener in the proper place, peel off the label.
Until RVs are built more identically, you will never get a handle on the problems as each unit will have different problems. This is not the worker's fault, it's poor setup of manufacturing. I have removed wall panels in my TT and entire rows of staples missed their mark. Unfortunately, some were driven into hidden 12V and 120V wiring.
This won't be cheap because you have to sell a lot of similar units to spread the cost of the fixtures, etc over all the units made with it.
Steve