Those *TERRIBLE* Thermarest bunkends. How to replace?

[KDOG]

Been fighting with this issue since shortly after the year warranty went (of course!) I am VERY perturbed to say the least. My trailer is a Kodiak 195. They are a terrible design (something the company knew when producing them, or so I've read). The collect water near the top seal and stain from the standing water. But that wouldn't be so terrible if they didn't pull out of their seal. The last one RIPPED off its seal and I had to fight, rant and scream practically to get them to replace it. Still cost me $250. Anyway the replacement bunk end wont stay in its channel on the frame either, keeps pulling out. I've just about had it. I would like to find a way to put another bunkend in there even if mods have to be made. Would love to find a way to use lighter material and the flexible tent poles to come up with a new one. But I'm wondering if another manufacturers' bunk ends will work in it like the ones off Rockwood hybrids etc.