Excessive roof flex on a Rockwood. How big of an issue?

[re5513]

I'm looking at purchasing a used, 2018 Rockwood 3029W WIndjammer and while doing a detailed evaluation, got up on the roof and walked around to inspect the caulking (which seemed in order). However, I noticed toward the front that one of the seams had excessive give that I didn't notice around any of the other seams. My question is whether or not this should be a disqualifier since it could lead to a potential failure of the seam down the road. I suspect the answer may be along the lines of "it depends" as there may be ways to shore up the seam from inside the coach though I'm not sure that the styrofoam insulation and ductwork would allow access to the exterior seam given the roof appears to be of a pressure, laminate construction anyway. What do you think?

My concern is that most all the other seams on the roof like the one shown here are very sold. It does not matter if you step on one side of the seam or the other, there is no give. In the case of this seam towards the front of the trailer I can see some give around the seam as if there is insufficient backing material behind the roof membrane. How common is this type of a problem with Rockwood coaches? Here is a video that shows what I'm referring to:

https://youtu.be/amckgyrxrug