I just started implementing my ComfoAir Q350 using regular Modbus TCP binding.
All you need is the Zehnder ComfoConnect PRO connected to your LAN/WLAN and enable Modbus TCP in the WebGUI.
You can find the Modbus Reference at the bottom of the page or use this direct link ComfoConnect PRO technical reference
I have not implemented every function already, but control of the ventilation level and AUTO/Manual mode is already possible. For me this seems to be the most simple solution to integrate your Zehnder Q-Series to Openhab. I hope this simplifies your integration too.