Any proper list of Mac firmware versions (Boot ROM versions) and the corresponding macOS version?
There is a blog from hoakley under "The Eclectic Light Company" webpage that tries to list the most recent firmware versions for different Macs and also tells with what OS update you can get them:


"Which EFI firmware should your Mac be using? (version 3)"


There are also two earlier versions of that page:


"Which EFI firmware should your Mac be using? (version 2)"
"Which EFI firmware should your Mac be using?"