Running more air than is needed is no big deal to me. I want the max load carrying capacity and the least amount of sidewall flex. Sidewalls flexing generates heat which kills the tire. I don't think you will ever wear a tire on a trailer out because it is over inflated. They will wear unevenly if the alignment is off or they will time out from old age. I always run my tires at max inflation. Never had a problem, just my opinion.
B.O.