Calvin(aka FastEagle) likes to throw out all the government manuals with suggestions and recommendations but never any requirements or laws that are in place once the vehicle has past the first time purchase.
Please show the applicable law that requires the owner of a RV to install tires that exceed the axle capacity. Only meet the capacity is required.
Use a little common sense here, if you have 6084# of tire capacity on axles rated for 6000# what will overload and fail first? On top of that, by Calvin's own recommendation, for a ST tire to have any chance of surviving is must have 12%-15% of excess capacity. So, with the higher rated ST tire rated at 3520# it must have a 15% reduction in capacity of approximately 500# making the real capacity less than the LT tire. The LT tire needs no reduction and will run all day 24-7 at it's rated capacity.
Keith