I reworked your piston to use any number of Thermostats - just add as many as you want to the initial thermostatList variable. I will create a tile for each thermostat and doesn’t require any editing of the piston (note that I only tried with a single thermostat but it should work with any number…).
Note: when using “Auto” rather than “Heat” or “Cool”, the thermostatSetpoint is 0 - I assume the coolingSetpoint and heatingSetpoint should be used instead.