Sagging bottom below queen

[timelinex]

I've got a 2021 381 and I am in the process of trying to optimize it's hook up to my truck. For it to be level, the rear most part of my bed is 5" below the bottom of the trailer, which is less than the recommended 6". HOWEVER, something I realized is its because where the bed rails are, the exterior panel is actually slumping 1"+ in that area. Is that normal? Seems normal since it's not like there is any damage and it just seems like they poorly optimized where they screw the panel into the frame. The screws are pretty far from each other in those areas. Any input on if that is normal?

Also, seems like I may be ok since if I was to come up on a situation where 5" isn't enough by 6" would be, it would just gently push the outside flexible panel and not actually hit anything hard till the 6"+. Opinions?

[WhittleBurner]

If it is just those panels, is it possible to locate the crossmember of the frame? Then drill pilot holes and add screws.