A warning for anyone who is using local keychain: Don't. Either give in to iCloud keychain or use a different secrets manager.

If you're using a Mac with a T1 or T2 security coprocessor or Apple Silicon, your local keychain can only be decrypted with a key stored in those chips. Your backups are useless. I figured this out the hard way when an Apple depot repair for a failed display flex somehow ended up with my logic board getting replaced as well. After reimaging from backup (SSD was integrated on the logic board), the keychain was unreadable and I lost several accounts without recovery options. AppleCare's response was, well, you should have backed up your files, even though I had...