So this video is 2 years old...but provides a good look at how the walls play a role in frame flex, before the frame gives up. So my take is this....it is my understanding, that Lippert builds the frame to the builders design in most cases. Lippert is saying, that the wall attachment coming loose, is the eventual nail in the coffin when the welds or steel tubing breaks.
Since I have replaced so many interior and exterior screws that lacked sufficient thread (Clamping strength), it isn't a stretch to question whether the same mistake is being made at the wall attachment points. It is a tough thing for us, because we have no way to inspect that connection, before it becomes a major issue.
The only idea I can come up with, is an outside angle trim piece, that allows the bolts to be accessed and tightened/monitored. That would require frame holes to maybe be threaded, or nuts welded to frame, so a wrench is not needed on both sides of the connection.
This video, is most certainly at the heart of any dispute, if there is one with any of the RV builders vs Lippert. I can see this happening with every 5th wheel being built and not just the toy haulers eventually. If I EVER get into this issue with mine, I will be creating a Frakenstein-camper, never seen before!! LOL.... I just don't buy that a fix, that can be accessed and maintained, is going to add any meaningful weight...I just don't buy it....