Hello. I've been away from the board for a few years, so please forgive any loss of grey matter or lack of familiarity with the latest knowledge.
The CTZ file has been submitted to support by email, but I'm curious as to whether anyone has had any success with this model year. O/S is 12673958. The supported models lists the Chevy SS only through 2016, but does list the 2017 Holden Commodore / HSV as supported. Current EFI Live 7.5 shows all the VIN, O/S, MFG info, etc but returns an "unrecognized PCM message, and obviously cannot edit the tune.