Yep, got the following setup now: Enabled WiFi/Ethernet over USB using OpenSSH with a public/private keypair set to auto-start. Now usually I don't require the SSH access, so I just turn it off with ;un. If my Kindle decides to turn into a brick I can now simply restart the Kindle and the WiFi/Ethernet over USB possibilities + ENABLE_DIAGS are at my disposal to save the system.