So...in last months Trailer Life they had a beautiful Dynamax 5er. I always loved those huge Dynamax Campers....but not on my salary ! I digress....anyway, did you notice they are running LT tires on that 5er ? I wish I could get some solid info on running LT's on my trailer.
Everyone I've talked toand everything I've read, the people who have made the swap have 0 regrets. IIRC, no one has a 15" Load D LT, so I think you have to upgrade to 16". If you have the room, go for it.
When I have to replace mine, I will definitely try my best to swap to 16" LT. A little more height would only help my bed rails to 5er clearance.