Always keep your USB patcher drive. If you reset NVRAM (Option+Command+P+R), your Mac will try to boot natively and fail. The USB is your "key" to the operating system.

Officially, Big Sur supports Macs from late 2013 onward. With a patcher, you can run Big Sur on models as old as:

Allows you to receive official Apple software updates directly in System Preferences.

Would you like a direct link to either resource?

Apple’s macOS Big Sur (version 11) marked a major design and architecture shift, dropping support for many older Mac models. But if you own a Mac from 2012 or earlier, you aren’t necessarily locked out. With the (specifically the Patcher Full version from Patched Sur or OpenCore Legacy Patcher), you can breathe new life into your aging hardware.