I installed successfully big sur release candidate 2 in my laptop Dell with core i5 broadwell processor.
I haved the same issue in boot, only used the premade EFI folder for skylake and added my ssdt, dsdt, kexts and config.plist i used in Catalina.
hello
I try get brightness but didn't work
and try too get battery status
my Laptop is Dell Inspiron 5548
http://s000.tinyupload.com/index.php?file_id=14701869023250759909
Thanks for all