Bottom bracket wear

[11.4]

What happens if you use a bulletproof cartridge bottom bracket like a BB7710 (basically the old 7700-era Ultra bottom bracket) and a pair of Octalink cranks. I know you lose your power meter, but try it for a month or two and see what happens.

You had mentioned you used the high-end Wheels annular bearing set, yet it also failed on you. If the issue was a skewed bottom bracket, that Wheels bottom bracket should at least have minimized bearing failure.

Is your chainring perfectly planar through a crank rotation? If your bottom bracket shell is forcing the bottom bracket out of alignment, shouldn't it be reflected in an out-of-plane chainring?

Last, SRM has had episodic problems with bottom bracket milling being slightly off kilter -- their Octalink bottom brackets sometimes weren't concentric so one crank would bring the pedal in and out during a crank rotation. The same happened with their later Dura Ace models (hollow shaft) and was almost a chronic problem in tapered square spline days. This has mostly been seen on track cranks, possibly because they are not a high-volume product and cranks were milled more by hand. Long shot that the crank is out of alignment? I'm not sure that it should be killing bottom brackets like this, but looking for issues.

I've worked with track cranks for over forty years, and almost exclusively with track equipment. I might even have been at it longer than Old Potatoe. I'm always discovering new things, but in all that time, with a lot of screwy track frames, haven't seen a failure rate like you describe. It's got me curious and I'd love to know how you diagnose it in the end and how you fix it.