At last, I managed to connect my Lifedomus gateway (and its nearly 100 devices) from Delta Dore with HA, and give it a second life, as it is for now (despite its discontinuation) the only gateway from Delta Dore that manages above 32 devices, which tend to be a step you reach very quickly as soon as you begin to do serious home automation.
This integration does not rely on MQTT broker, but it does not yet tick all the checkboxes of the HA development standards (need to externalize all the network communications to a PyPi library), however it is already fully functional and responsive.
I work on it since several months (years?), and I tend to be very reactive in its development – especially regarding potential fixes – as it’s my main automation system and that I have quite various devices: alarm, lights, motors, power managers, heaters, sensors, etc.
Feel free to have a look, give a try and send me your comments.