Hi @Rednest
I have another post about this questions check HERE.
As far as I understand almost all smart heating radiator valves work with Nest Thermostat but don't communicate with each other.
If you look at the support page of the Nest Thermostat: https://support.google.com/googlenest/answer/9259740?hl=en-GB#zippy=%2Cradiator-valve-basics%2Ctune-...
Also found an answer on Reddit:
The nest will continue to pump hot water around your system, but the individual radiators will shut themselves down as each one hit's it's target. As each rad hit's temperature, the flow will be increased to the less efficient radiators or harder to heat rooms so they will reach temperature quicker while the temperature is maintained and those that have hit target. Once all the radiators reach temperature and water can't flow any more (as long as you don't have a super old boiler) the boiler will stop the flow anyway. Or when the thermostat reaches target that will stop the boiler.
Edit: Additional: Think of it like this (and I am guessing you have a regular system boiler), the thermostat turns the boiler on and off and that's all. If the nest were to connect to the individual radiators, it couldn't do anything to limit hot water to one over the other. So the TVR is an extra step to balance heat around the home to all rads.
