Never one to do things the easy way or the correct way, on my test rig (Z390 Pro Wifi, i5-9600K, RX-580) I updated all the kexts to current versions and a couple of days later updated to 11.2.1 while running OC 0.6.3 and using the Apple built-in updater. No issues whatsoever. I had the normal number of reboots and 20 minutes or so of twiddling my thumbs. A couple more days and I felt ambitious enough to create a new config.plist for OC 0.6.6. I followed the Dortania instructions for setting up and using the new launcher and everything worked fine off of my test USB stick. I then did the transfer of the new OC files to the test rig. No issues, no glitches. And everything works fine, except for controlling volume through Displayport--but that is a different story about the "feature" that Apple has provided us (or not). Now, to just find the same motivation to create a new config.plist for my main rig.......