Didn't have a single blackscreen in 20.1.3, got one within 30 minutes of playing a game in this one..
backwards, forwards, backwards.
The main culprit was BF4, I hadn't played it in previous drivers and was feeling the itch to play. It's a hard trigger for black screens in 20.1.4. Most other games seem fine still.
New issue which I hadn't had in older drivers, system hangs when restoring from sleep mode. Which I thought they fixed in a previous version.