I will try to find where's the problem with keys, but for now I've updated to Big Sur and it's quite good, but fans are starting more often compared to Catalina, for now I will let Big Sur settle down and report after day or two.
There was problem with wifi when I installed update, but it can be fixed by removing "AirPortBrcm4360_Injector.kext" from "AirportBrcmFixup.kext/Contents/Plugins/" (don't know if this step is required, but I removed this file anyway) and modifying AirportBrcmFixup.kext loading in OpenCore config.plist (it's required to add AirPortBrcmNIC_Injector.kext before AirportBrcmFixup):
Code:
<dict>
<key>Arch</key>
<string>x86_64</string>
<key>BundlePath</key>
<string>AirportBrcmFixup.kext/Contents/Plugins/AirPortBrcmNIC_Injector.kext</string>
<key>Comment</key>
<string></string>
<key>Enabled</key>
<true/>
<key>ExecutablePath</key>
<string></string>
<key>MinKernel</key>
<string>19.0.0</string>
<key>PlistPath</key>
<string>Contents/Info.plist</string>
</dict>
<dict>
<key>Comment</key>
<string></string>
<key>MaxKernel</key>
<string></string>
<key>PlistPath</key>
<string>Contents/Info.plist</string>
<key>Enabled</key>
<true/>
<key>MinKernel</key>
<string></string>
<key>ExecutablePath</key>
<string>Contents/MacOS/AirportBrcmFixup</string>
<key>Arch</key>
<string>Any</string>
<key>BundlePath</key>
<string>AirportBrcmFixup.kext</string>
</dict>