Nest did support Energenie TRV heads, but when Nest became google this support was dropped, I got the Energenie TRV first, then came to add Nest 3, with the Energenie software you could change the temperature on the Nest wall thermostat and the TRV heads would follow, as designed, but if Nest temperature is changed by turning the dial or a scheduled change, the Energenie my home failed to follow. So I called Energenie to ask for help, to be told Nest has withdrawn support.
In real terms since Energenie is lower than the Nest wall thermostat it needs to be set around 2 degs C lower, it is wrong way around anyway, the TRV should tell Nest not the Nest tell the TRV, so setting the schedule to match works fine, and using IFTTT you can even set the TRV to make same changes as Nest with Geofencing, only bit that does not work is turning the dial on Nest Gen 3.
But whole point is where the wall thermostat is placed is controlled by what conditions you want to stop and start boiler, not what temperature you want the room, yes related of course, but just as in my hall I have found by experiment I need 2 degs C difference between wall thermostat and TRV so it can be set anywhere else to suit.
It is not where I would expect to see a thermostat, however for what is wanted it may work? In my mothers house had two wall thermostats as windows west and east so one controlled morning max, the other the evening max. Room temperatures controlled by TRV heads.
