you can't boot the arm Macs into target disk mode, you can only boot to the recovery os and share the drive - it shows up as a network share iirc. I was super annoyed by this a few weeks ago because you can, for example, use spotlight to search for "target disk mode" and it will show up, and looks like it will take you to the reboot in target disk mode option, but once you're there it's just the standard "choose a boot drive" selector.
olliej|1 year ago