I am running (well, it is ordered, not there yet) the exact same config as @Pandabeer40
Obviously I would very much to have this integrated in HA. As fas as I know it comes with an app to control the thing: BAS unit which seems to be a simple wire connection to the heater. The real cleverness is in the wifi module connected to mains. How and what? Dunno yet. Happy to help testing by then!
Maybe it could be something like the Baxi thermostat (BAXI TXM / RXM 10c OpenTherm thermostat - HA integration) which basically is the same as the Remeha e-Twist (which I will get).
Mister Domaray did a nice analysis and seems to have it working using node-red and some API trial and error: http://domaray.com/2021/12/21/termostato-baxi-connect-integracion-en-home-assistant/ which is in Spanish but we all know google translate for your local language 