Of course they don’t, or people wouldn’t have to be reverse engineering things.

But it doesn’t affect your hardware warranty.

What was your point?

I don’t understand what you mean by criticizing it for not being officially supported.

They do officially support the Permissive security policy, and it is intended to allow you to boot custom kernels. Running a fully-untrusted operating system kernel is an intended feature, even if they aren't going to give you support if something breaks in the upper layers.

See https://support.apple.com/guide/security/startup-disk-securi...

Yes, they do