alt Hacker NewsAsahi Linux already does use an open source UEFI implementation (U-Boot) to boot Linux.
https://en.wikipedia.org/wiki/Das_U-Boot
The Asahi installer will also allow you to install UEFI alone, in case you want to use UEFI to install some other OS.
The hardware management engines in modern x86 chips are backdoors running at a higher privilege level than the installed OS's kernel.
It's hard to see them as anything else.
Apple's Secure Enclave and ARM's Truszone work the same way as Intel ME and AMD PSP. All of them have a separate specialized minimal OS running on a specially protected memory that cannot be accessed by the normal OS.
Apple can lock your Mac just like other manufacturers can do via Intel ME. All of them are backdoors.