Boiler automation with multiple Thermostat inputs

I want to control a gas boiler based on rooms reaching target temp.
I have multiple zones but If I figure one zone, the same will apply to the other zones.

Original system…
System gas boiler with EPH timeclock - simple relay control, not Opentherm (I have DIYless, but this is a project for another day)
Based on the timer schedule, 220v is fed to the zone actuator/valve.
When valve is fully open, actuator microswitch calls for boiler, boiler comes on, boiler is regulated by wall-mount analog thermostat.

Stage 1 - Remote timeclock…
I added a 4-relay board + ESP01 to switch on and off zones. I can now switch on and off zone from HA, so can manually switch zone on/off or from scheduler card.
I have an automation that turns OFF any zone after 1 hour as I have not figured Thermostat control.

Stage 2 - Shelly TRVs…
I replaced radiator valves with Shelly TRV except for Bathroom (valve always open for safety).
There is a Shelly TRV in the location of the Thermostat, but this is set to a high temp to allow analog Thermostat to regulate boiler on/off.

Stage 3 - Xiaomi Temp/Humidity sensors…
Added these to bathrooms so I can check temp (humidity unimportant, but interesting)

I need HA to turn boiler on when there is demand for heat and switch off when target temps are reached on all rooms in the zone. In my sample Zone, I have 2 rooms with Shelly TRV, 1 Analog Stat, 1 Xiaomi Temp/Humid sensor in the bathroom (valve always open)

Long time lurker, first post. My apologies if this has been asked, I don’t think it has.
Big thanks if you got this far!