Nest Thermostat and Fibaro switch

Hi. I want to buy a Nest Thermostat v3 and connect it to Google Home and Homey Pro. I am not so sure if the thermostat and homey can do what I want it to do. I want to make flows that turns on/off a Fibaro (z-wave) switch when the thermostat turns on/off the heater. In the homey Nest app I don’t see events like “When heater is on” or “When the heater is off”, only “The temperature changed” and “The target temperature changed”. Should I use these events and store the values in variables (tags) to let conditions do turn onoff the Fibaro switch in the flows? Are the tags global variables?