I replaced the original RoadRider D tires on our Crusader 209RLT after 2 seasons and over 10,000 miles with Gladiator load range E ST tires, and have had no issues.
I strongly advise you add a TPMS system for peace of mind when towing, as it takes the guesswork out of the trailer tires' pressure and temperature while towing.
Jim & Kathy
2012 Crusader 290RLT TE, TrailAir flex pin: 2012 Toyota Tundra 5.7 SR5 Dbl cab 4X2 Tow, 4.30 gears, RideRite air, TRD cold-air induction & dual exhaust: Reese 16K Slider: TST tpms
Miles towed to date: 18,950 Nights camped 192