Many thanks to all replies & thanks to Tim for shifting my post to the correct location.
Plan is to put it up in the warm spring sun on the driveway. I’ll check out the webbing straps as ChrisR mentioned. Yes, the rear flat panel that then joins the panel with the filler cap was visibly flexing, and the seam between the rear wing was obviously flexing as a result. That was my main concern or worry. I’ll get some serious heat into it before putting it up “proper” but the stress on that rear deck did concern me, & certainly would leave me with sleepless nights if I kept it up.