In the last 13,000 miles I have always run the max pressure. The trailer is most always at max GVW, to the limit on axles. Tires haven't lasted at all. First set was eaten by the axle alignment, second set just wore out in 7K miles, they were Goodyear Endurance.
SO this time I am taking a chance on tires from E-Trailer. They are Providers, 14ply, chinese
run them at the recommended #100 but they have a load rating of over 8K per axle, still the light weight 6400# Lippert axles. The next move will be to replace with 8K axles.
One thing I will say for the 14ply tires, they do track down the road better than the 8 plys did. Time and distance will tell how this works out.