If you already integrated
zigbee2mqtt in your Home Assistant, you can use the Eurotronic Heizkörperthermostat. I use them on all of my radiators except one (just because I had a spare
Fritz DECT one and was too cheap to replace it ).
I used the eq!Max Cube and its thermostats before, and it was a disaster! Neither
node-red where able to control them reliably. This was not due to my routines, but rather -mostly- to the fact that there is a limit on how often you are “allowed” to control these devices per hour. I don’t remember the exact formula on how to calculate this, but basically the more thermostats you have, the less you can control them in total per hour. Unless you power cycle the MaxCube manually all the time. In it’s defense, I had not used it with Home Assistant (because I had switched to the zigbee thermostats before getting into HASS).
Either way, the zigbee thermostats are way less frustrating; you can auto-discover them via mqtt discover, and everything works out of the box except for settting temperature. But you can do this via
mqtt. I have Xiaomi Aqara sensors on each window, so when I open a window, the thermostat will turn itself down and right back to the previous value when I shut the window again.