I was able to create the bootstick from within Catalina, no problems at all, please see Image 1;
I inserted your EFI, just swapped OpenHFSPlus.efi for the older HFSPlus.efi;
but then I got stuck again at the apple (see Image 2), no idea why;
my 33a Firmware settings are just like...
... but after creating the stick from within Catalina I have to swap in your EFI, am I right?
because my Catalina EFI is from early April 2020 and would not work with Big Sur I think;
at this time, I had some issues with sleep/wake and other minor problems that you solved ...
... please look at
so you will see there's no reference to gibMacOS;
but now I'll create a new installer and report to you later ...
... I have another SSD with Catalina (as I told you), but it's disconnected;
when connected, I'm able to boot it, but I don't want to mix it up with the desired installation of Big Sur;
and there are no older MAC OS installations on my machine;
I know that the SmallTreeIntel82576.kext is just...
... first of all, thank you for the hint with space bar, it works fine, and I reversed the changes I made (HideAuxiliary and AppleDebug);
and yes, I created my installer step by step according to the oc 0.6.6 guide;
in the folder 'com.apple.recovery.boot' I have the BaseSystem.dmg (655420141)...
I did what you recommended, but I had to change the following two settings:
without changing that I saw just my Windows 10 boot option;
with these changes I see additionally the USB Stick and the Clear NVRAM boot options;
but I'm unable to boot, please see...