In October of 2020, WE bought our first 5th wheel, a 2015 Heartland cyclone 4150. From what we can tell, it was left on a seasonal site since 2016. I am thinking the tires are original, and although t...
IMO G-rated tires are unnecessary with your application. As was mentioned by JIMLIN, all the reasons he noted work on your trailer.
I have a similarly equipped 5th wheel, and I put Sailun tires on it about 7 years ago. But when I replace them, I may go to LT tires as I have weighed each wheel and I only have a max of 2500 lbs. on two wheels. However I may stick with the Sailun due to them being cheaper than new LT tires. Go figure.