With only 80 psi in those heavy tires they can heat especially on the downwind side in strong side winds.
Ever watch a motor home lean going across I-40/I-70/I-80 in strong north or south winds. The down wind side tires look half flat. I would add 6-8 more psi for load changes a tall heavy boxy vehicle for dailey dynamic load changes.
The 80 psi is a minimum pressure recommendation for static weights.
I would imagine the folks over in the motor homes forums that probably have the same MH can give you some input on what works vs what sounded good in their motor home.