Many thanks for your post and linking to Hörmann garage door via MQTT - #83 by virtualdj
I’ve been wanting a garage door open/closed sensor in HA for a while but all the hardware that seemed to be involved put me right off. After reading your post, following a few links and installing the Passive BLE Monitor integration I have garage door open and close status in HA (via RPi onboard bluetooth interface).
The integration automatically detected the door opener and created three sensors.
What a result - thank you and to @Ernst for the integration.