I dont know the reason for moving the Thermal throttle down from 85c to 75c. but its time to change it back.
my undervolt before i uppdated to 19.3.3 from 18.12.1 was 1600mhz stable on my vega 64 at 81c.
i want to have the newer drives due to the more stable Radeon overlay. i used to have a problem with it not responding to hotkeys.