I've tried 65 psi D rated which were higher load capacity tires than OEM 80 psi E tires.
They were dismal failures. The truck handle much worse than the OEM tires.
HOWEVER... both trucks were carrying max RAWR loads. One had a tall heavy 11.5' truck camper and the other was a DRW one ton in commercial service carrying max RAWR loads with a 21k fully loaded GN stock trailer.
IMO you can get education over on the truck camper forum on 65 psi vs 80 psi and carrying heavy loads. Check them out. Or ask a them a question.
