Recommendations for virtual thermostat HVAC (NOT TRV) control with external room thermometers

Hi All,
My use case is to have a virtual thermostat that controls one or more physical thermostats (trane / nest) but leverages the room temperature from a defined thermometer in one or more rooms (may move to presence based in future).

I can find implementations such as better thermostat etc… but these seem focused on European housing with individual TRV values on the radiators, and look to leverage a switch which is not available to me as I only have climate entities.

I want to be able to set the virtual temp, and leverage the room thermometer data to control or drive an offset.

I am sure that this has been done with HVAC systems, I am just not able to find the correct search terms to find some solutions that have been done before for HVAC AC / Furnace configurations.

thanks for any recommendations or pointers.