I have been trying this procedure on a brand new 2023 MacBook Pro M3 with Sonoma 14.1, and when I try to install the AppleFWAudio pkg, it still gives me a pop-up that it can't be installed because it's from an unknown developer. Am I missing something with that install? When I try the next step (sudo chown ... ) in terminal (in either normal or recovery mode) it says it file doesn't exist.