In the beginning we used truck tires (LT) or passenger car tires (P) on our RVs. In the '70s American tire makers gave us the ST tire which was a compromise between the P and LT but more importantly as Goodyear said "the ST tires were economically priced". They were to be used on trailers only and not suitable for use on other vehicles.
I've owned several different RV trailers and many different sizes of equipment trailers for my business. After taking possession of any trailer the first thing I always do is dump the ST tires and go with a LT. It may require changing wheels or modding the trailers suspension but for zero issues with tire in the long haul its worth it for me.
I run LTs on my RVs for seven years average and in the 55k-60k mile range with zero issues at any speed I choose. My equipment trailers were on the road much more and have ran many a set up to the 70k range however those miles were in 18-24 months or so. That sold me on LT over and ST.