Big Sur was finally released, and took the plunge "early" as usual.
I did the update from a working Catalina 10.5.7 that I previously updated to Opencore 0.6.3 from 0.6.2 (haven't posted 0.6 versions because it's an older board that few people seem to use anymore)
That being said, in case there are lurkers, I'm sharing it here. Only serials need to be changed.
Opencore 0.6.3 was a bit more involved on the Opencore side, but that's to be expected. The jump from 10.x to 11 is a departure no doubt, and there were more updates than previous point releases, took me a couple hard fails to get it working.
I've moved away from using opencore's bootpicker entirely.
OpenCanopy's really slick, and I would have loved to keep using it but since I dual boot with windows, it messed with the activation, and Game Pass for PC.
So I'm dual booting using the UEFI (bios) drive picker, where windows doesn't think it's a macpro 6,1
As far as BigSur is concerned, I "just" booted it. Everything checks out so far, Not sure about the look, but that's personal.
It's really smooth, no regrets on the rx580 whatsoever too.