I'm sad I went for a WiFi based solution many years back (Tado). They say cloud costs are getting too high and are suddenly super aggressive in limiting API usage. Give me a fully working local API then, you twats.

I haven't found a good local-only or ZigBee based system that allows precise room control that controls the central heater efficiently based on demand. I could get a bunch of ZigBee radiator knobs, but then I'd have to do a lot of programming/automation to get a good system as a whole. I have to say that Tado does that brilliantly (that's why I chose them in the first place)