Thanks Yves, really appreciate the follow-up - I omitted to mention that I am using the community MiHome enerGenie eTRVs also in addition to the central Hive thermostat
[RELEASE] MiHome (Connect) V2.0.1 [Energenie] (not Xiaomi MiHome) https://community.smartthings.com/t/release-mihome-connect-v2-0-1-energenie/62385
- should have mentioned that before - my apologies
Using what you have provided as a solution should really unlock the power of this setup to refine and augment the heating optimization using ambient temperatures, weather forecasts and individual zone/room/radiator settings - thank you my heating bill should improve thanks to you - great stuff!