I've also had some dead boards at recommended settings. I've been very careful and understand the risk. I wouldn't have bothered posting about it because I know their can be consequences. What the other poster stated was true, although it has been a small number in my situation. To be clear I'm not blaming or crying, I know what can happen the minute I flash a aftermarket firmware.
EDIT: I'm trying the firmware on S17 56T, S17 50T Pro, S17 53T Pro
Yeah lot of people are trying to push their machines way beyond 70th/s which I mean I can't blame them but if you don't have the cooling to do it. It isn't worth doing. Better off shooting for a mild 15-20th/s increase where no one has issues than going into uncharted territory. At least that is my input on it. We provide a few settings on the website to attain the small overclock and to attain a good underclock/undervolt. Those should be a baseline and there really is no need to go away from that unless you have free power and are willing to risk it.