I see that they use a configuration similar to my computer. My system today is Catalina with clover v5122 and I can't migrate to open core, much less to Bigsur. I tried to follow the procedures on the dortarina website but I have difficulties. My configuration today is: GA-X79UP5...
I manually selected the initializations because the partitions were as hidden before and so it didn't work>
At boot press F3 and the hidden options will appear;
Then you must select in the following sequence:
1st boot = Install from MacOS
2nd boot = select Pre boot loader (not FileVault) and...