So I finally found the limit to the 72A 'thane after repeated abuse. It seems if you put a few thousand miles (a few 1.6 megameters) on these and hit a few broken beer bottles along the way, then torture them by powering down a 1km (0.6 miles) gravel railroad access path, then that’s the limit they can endure
That being said, I don’t know anyone (else) who rides polyurethane longboard wheels on gravel roads… I neither recommend it nor enjoy it. I was in a tough situation where I didn’t have enough battery to go a different way. So this is unlikely to ever affect you. But we have found the limit.
These are the best street wheels I’ve ever used though for electric longboarding.