OMFG; I am in Perth, I have the same system, the very same problem and solved it almost the same way and was in the process of writing it up.
The system uses RS422, with a base64 encoded AES key in the aaservice binary, and I was contemplating building an esp32 based open source implementation of the controller.
The system uses RS422, with a base64 encoded AES key in the aaservice binary, and I was contemplating building an esp32 based open source implementation of the controller.
That's a crazy weird coincidence.