Yup. On M1s Apple tries to make all external chips either use runtime loaded firmware or be bootloadable, both for security and recoverability reasons. I don't

Yup. On M1s Apple tries to make all external chips either use runtime loaded firmware or be bootloadable, both for security and recoverability reasons. I don't know if it's possible to truly brick an M1, but if it is you have to try really hard.