This looks perfect for My Central Heating Solution using Thermal Actuators
You’ve got the Thermal Actuators on your manifold already, so you’re already appropriately zoned.
Then you’ve got choices for temperature sensors to feed into it, either basic like my ESP8266/DHT22, or something different.
Do you want to be able to override the temperature from a unit on the wall, like you’ve got at the moment, or are you happy without per-zone on-wall adjustment, and either leave it to the automation, or utilise other ways (like I can use the openHAB app, or Google Assistant or Alexa)
If you’ve got any further questions on my setup that’s not in the linked thread, please feel free to ask!