I just counted all my fast charging sessions (varying amounts of charge from 3kwh to over 50kwh) and I have fast charged over 135 times since June 28 2019, mostly at 50kw chargers and yet, I have no noticeable degradation yet.. However, I rarely charge past 90% and I rarely drop below 10%.. I have only charged at chargers > 50kw 3 times... It's mostly my addiction to free juice that makes me use DC fast so frequently.. If I couldn't charge on them for free, I would be charging at home most of the time.