based on the work of of Xrucka which is based on the work of im-0 which is based on the work of Thorsten Traenkner, I created a component for controlling the Bluetooth thermostats created/distributed by EUROTronic / Xavax / Sygonix / alike - found here.
It’s very basic for now, but you can already reliably track resp. change the current resp. target temperature of multiple devices.
Feedback is welcome. Development is ongoing. Thanks!