As a park of the pre delivery inspection (done at the dealer) everything should be checked to make sure it works, this would include the tire pressure. With being your 3rd new trailer this is probably redundant to you, I would not worry about the tires until you get the trailer fully loaded and weighed ready for travel then look at the Goodyear Endurance us made tires and get the size and load rating to match what your trailer weighs.
Mike & Emily-Sacramento, CA
Our 4th trailer (2016 Aspen Trail 1900RB)
2018 F150 STX 2.7 Eco Boost