Hello,
I've installed Big Sur on my Latitude E7470 using OpenCore. The only issue is that the brightness controls don't work. Unfortunately, also outputting to an external monitor blanks out my Laptop screen. I've tried applying USB fixes and it's still not working. I've made my own config.plist and OpenCore Installation and also tried your installation files for Big Sur and the same things aren't working. Is there a fix anyone else has been able to find.