This piston synchronizes any smart lights and smart switch. The switch will work like a normal light on/off switch for lights but, if all the smart bulbs turn off (with voice command or app) then the switch will also turn everything off. For example:
Switch turns on - lights on
Switch turns off - lights off
When any light turns on - switch on
When all lights are off - switch off
This piston just allows more options to turn lights on/off when using voice commands or the SmartThings app.
Let me know your thoughts and see if it works for you!