You need to find out what your axles ratings are on your trailer for certain before deciding which way to go. Those Tow Max tires are delivery tires so getting them off is a wise decision but without axles rating you are guessing.
Do a search in this forum for "China bombs" and "XPS RIBS" and read some of the threads. There is a lot of good information, opinions, facts, hearsay and poppy cock to fill a few hours of your day.
I moved from ST to LT and then ultimately to the H rated 17.5 inch wheels and tires like ME AGAIN suggested in the post above. My LT's were excellent compared to the ST's that had bulges in both the sidewalls and the tread from internal failures. I caught them before they blew. I move to the H-rated tire for capacity after upgrading the axles and when I wanted new wheels.