Are you saying that hanging large RV diner size windows using the sheet metal as a frame is insufficient, the windows could sag the framing area over time, therefore the window frame should be welded, riveted to the other studs and headers, boxed in... to create a stronger support? Small windows would create no problem but large RV sized diner windows, lots of weight over thousands of miles equals distortion if their is insufficient framing to support it?
That makes sense when you think of the road vibrations the windows get subjected to as you drive over bumpy roads.
Are there any webites from the conversion manufacturers or anyone else that has a drag and click program for laying out floor plans in an RV setting?
"I have marveled often at the thin line that divides success from failure and the sudden turn that leads from apparently certain disaster to comparative safety." Ernest Shackleton, Antarctic Explorer, Sea and Land, 1874-1922.