I also experienced excessive tire wear on one side of my OFF-ROAD POPUP trailer. It turned out to be the wheel alignment weights were bounced off on this tire only. I had the tires replaced and balanced again and haven't seen any funny wear since... I also inspected the shocks on the trailer as well but they seemed to be just fine. My shocks however are installed at very large angle which concerns me about how well they are performing. I have plans to re-position the shocks to be more vertical. My trailer weighs in around 4200 lbs when loaded for trips...
Similar to this google photo
If I had lots of money I would install something like this Australia Kimberly design for independent wheel suspension.
Roy Ken