There are Smart TRVs that can wirelessly trigger a contact closure that will turn on a zone for the boiler. You could also listen to the (usually Zigbee) protocol messages and close a relay yourself if you have a home automation setup (either directly from Zigbee, or by gatewaying the Zigbee to MQTT and then responding to the MQTT traffic).

The problem with running a call for heat to the boiler (nearly) full-time is that that will run the circulator pump for the zone and, if there's nowhere for that water to go (because all TRVs are closed and there's no "loopback" pipe), the circulator is going to draw a lot of power and eventually fail from being deadheaded.