Some contributors and me developed a bridge between Comelit Simplebus2 and MQTT. At the moment just with basic functions without audio/video, but ringing, open, ring-to-open, etc. is running. An ESPhome firmware version is linked on this page. If still someone is interested in integrating Comelit Intercoms into HA which do not come out of the box with smart functions, maybe this could be what you are searching for: