I have run about 280 hours of prime + orthos + occt tests, in fact mine has run stress testing practically non-stop since I got it...first trying to sort out a reboot problem, which ended up being a software issue, and then trying loadline versus not, etc.

80% of that 280 hours (documented, actually probably much higher) is between 1.3625 volts (cpuz) up to 1.39 volts (cpuz). And still boot voltage at 4, and voltage for 4, 4.05, 4.1, 4.2 for 12hrs+ stability is exactly same. I have zero degradation after 1 month of near continuous stress testing at vcore 1.36 to 1.39.

I think stress testing simulates greater use. By way of example and not implying accuracy, 1 day of stress testing might equal 1 week of normal use.

If I saw degradation using two chips running stress testing with high FSB and ? high corresponding VTT, I might conclude that these chips dont like running with high FSB and/or high VTT, and that stress testing brings this fact to light quicker than 24/7 use. But I would not conclude, especially based on my chips (granted just one, but so is his just 2), that stress testing in itself is damaging, unless your settings are a problem to start out with, and stress testing just brings this to light quicker.