Although it's expensive, there is a aftermarket wheel that you can buy to convert your trailer axles to 19.5 medium duty truck tires. This about doubles your GVW rating on your tires.
You have to buy the conversion wheels with the trailer bolt pattern centers, and a 19.5 hoop. That allows you to put 14, or 16 ply, 19.5 inch tires on your trailer. The 19.5 tires typically come on medium duty Lo Pro trucks (roll backs, wreckers, Etc.) I have an old U Haul truck, and a chevy 3500HD box truck, that came with 19.5 tires, they're about as durable as an anvil, compared to the chinesium trailer tires available for trailers currently.
They offer a steel wheel, or a alloy wheel, that enable you to put the 19.5 tires of your current trailer axles.
Link to Boar Wheel site:
https://www.boarwheel.com/stop-trailer-tire-blowouts/
Yes, it's expensive to do the conversion, but so is taking off the side of your trailer with a blowout......
This company also offers a tire pressure monitoring system that can be installed on your trailer.