If OP is reading this, go to the Network control panel hit + and select Thunderbolt networking to get the adapter; you’ll want to pick up a Somnet or similar Thunderbolt to SFP+ box (the Atto 3102 may be necessary) which hosts an SFP+ port into which you can put whatever.

From the very beginning I loved firewire and target disk mode.

This also works with a normal USB-C 3 cable afaik. No need for actual thunderbolt.

Dupe