Plenty of ST tires are rated for more than 65 mph. Some of you are stuck in the 80's with towing technology, its getting a little annoying. My last trailer had Carlisle Radial Trail HD were rated to 81 mph. My current trailer has GY Endurance is rated to 87 mph. Just because they are ST doesn't mean max speed of 65 mph. Get over it. That said, I don't tow much faster than 68-69 mph because I can't afford the fuel it costs to travel that fast.
Most Chinese tires are under built, in my opinion. Pick up a generic ST tire, then pick up one of the tires I mentioned above. Significant weight difference. Having a tire designed to handle the weight (or much more weight) is ideal. Very few people know how much their trailer weighs. They are likely also running around on tires that are marginally acceptable for the weights. I always buy tires with spare carrying capacity and haven't had a problem yet.