I've also had those Trailer King RST's blow out on me way before their service life. Three on a single trip. Others have posted some brand recommendations already - I'm just chiming in to add three more thoughts.
1. If you can, definitely invest in a TPMS. These trailer tires are often inflated to 80-100psi and with these campers weighing so much (ours is 16250 "wet") that can be 4000lbs+ on each tire. That's an entire sedan sitting on a single tire. Being even a little low can put a lot of strain on them, and temperature has a big impact too. Towing in full sun can add 30 degrees right there, and you can become dangerously over-inflated just towing a few hours on a hot day if you don't know it's happening.
2. This requires a TPMS, but react as quickly as you possibly can to any blowout to slow down and pull over. It's not just common sense. Once one tire blows, the other tire on the same side is now carrying double the load! If they were already stressed, this makes things so much worse. One tip I learned from an old-timer but never tried myself is if you have a blowout, after replacing that tire, rotate the other (still good but stressed) tire to the other side of the trailer. I don't know if this makes much difference but I plan to try it next time myself. Almost every time I've had more than one blowout, it was always the "sister" to the tire that blew earlier.
3. Next time you buy tires, get the next load range up. Trailer tires are not actually all that expensive - my truck tires cost like $450 each, but I just put Load Range G tires on to replace my Trailer King Load Range E's (the ones that came with the camper) when those self-shredded. The spec on the info plate on the side of the camper is the minimum - you can always upgrade. They were only $15 more each, and it's good insurance IMO.