I agree with Old-Biscuit. Tires need to be adjusted to proper psi when cold. Yes, they will heat up rolling down the road, especially in the heat of the day. Keeping an ST tire at max pressure, as read on the sidewall will keep them cooler, get best mpg, due to less rolling resistance. For this reason, I never suggest to way over tire your trailer. An example...If you put G-rated tires on that FW, I would not suggest to air them to 110 psi, nor would I say just run them at 70 psi, per the inflation chart. That would simply not be the right tire for the weight of the trailer.
If your FW weight mentioned 8,200, is dry wt it will likely weigh 10K when loaded to travel, and even though the truck will carry about 2K of the weight, I'd still use 80 psi cold pressure.
Jerry