Sean: Re: worn tires. I think you may have a mis-aligned axle, or extremely non-conforming axle which is worth investigating this week, and here's why.
We have almost 10,000 miles on our 17 HRE with Westlake 235-785-15s that were filled with nitrogen. Same tire Wood River Pod has. This Unit was purchased while we were living in Alaska, and we brought it down the Alcan Highway, Cassiar Highway, into WA then ran the entire Oregon Coast; back through Crater Lake, Idaho, and all the way out to Western North Carolina. Since then we have explored the Blue Ridge Parkway up into Virginia and back.
Roads starting from Alaska, Yukon Territories & BC ranged from rough frost-heaved pavement, very coarse pavement, sharp (windshield cracking) gravel construction zones, smooth pavement, curves, inclines all the way up to smooth higher-speed Interstate running often at higher summer temperatures.
We never had a flat, never had to add any significant air, the deep Westlake tire lugs are not excessively worn, and there is totally even wear across the crown of the tires. I think it is a "Lippert" trailer axle, but I can check. Not sure if it is a 3500# or 4000# that HRE Pods come stock with, or whether there was a vendor change in who supplies the axles to FR. We did not add the FR optional lifting blocks to the axle.
Since you are having such extreme outside edge wear, you fully deserve to have this finally corrected. If they find the axle is defective and can't be corrected by shims shackles & adjustments, I'd consider making lemonade out of lemons by jumping a step up in axle durability rating, maybe put an inch or 2 of lift on it, and thus upgrade your way out of the problem ending with something much better that must be installed to your tire wear satisfaction.
Is this reasonable? I am truly sorry you have this $$$ hassle to deal with. It's as if your axle has an arch in it; high in the center & curving down beyond spec as you move out to each wheel hub. If you never remember high-centering over a big nasty boulder, this must be a defective axle from its maker, if it cannot be adjusted back into specifications.
I'm really curious as to what you find out on this. I hope things get solved so you can relax. Please let the forum know what you learn !
---brad
2 Questions for Jeff (Wood River Pod) because I don't know a huge amount about tires, beyond brand research:
1) Are the equivalent Westlake trailer 235-75-15 size tires really hard to find? Even at Hailey's Les Scwab?
Reason I ask is that I am old enough to remember almost EVERY car had that size-range back in the day. (I do get that any 14" tire is a 'tough find' for classic cars that weren't upgraded at least to 15s). But with so many muscle and classic cars being collected, would not a top-quality radial vehicle tire do an even better job than a trailer tire for our Pods?
I'm asking this out of ignorance, because I must have some pre-conceptions that must be wrong and wanted to get your knowledge on the subject, even though I don't need to replace the Pods tires until perhaps 2019 season.
2) You mentioned finding that "trailer tires" that size are hard to find. Wouldn't a "vehicle tire" be equal to, or stronger construction than a trailer tire? I always thought trailer tires had less quality, because they don't have to steer or part water for hydroplaning, etc. and have more stringent standards for manufacturer's standards of ride & handling. Do trailer tires have special characteristics that are missed by vehicle tires?
Really curious / want to learn from everybody
--brad