Ive been in contact w/ customer support for this issue that ive had for the past 2 months or so. There were several things they told me to do, and all of you have probably done them several times over.
After installing 20.2.1 (from 19.9.2) i got ONE Black screen.
What seemed to "work" for me (and by work i mean i haven't had a black screen in over a week), is by adding the following registry tweak. I also force closed MS edge at the time, so im not sure if this had a role aswell.
DisableHWAcceleration 1 (DWORD)
Doing this allowed me to play for several hours w/ no problems. Mind you i still do get crashes, freezes, but no black screens that force me to reboot. That's at least a step up.
The funny thing is i removed this tweak to test for a black screen and so far ive still havent had any. Edge is running aswell. IM not sure what the heck this problem is. It sure is a strange one.
Give it a try if you haven't.
After using the new drivers, im still not getting black screens, which isn't really that amazing as i wasn't getting them w/ the fix i posted above, but i am getting crashes still in video games like rdr2 (haven't tried many others yet) and the windows reliability history, apart from application hangs, lists HARDWARE ERROR aswell. So im still not sure what the exact cause of that is, but ill have to test this further to see.
I haven't gotten a black screen yet, but i do get hardware errors and that causes the radeon software to crash aswell as rdr2. RDR2 says err_gfx_state then closes.