That’s the right one.
Success! I bumped the Living Room thermostat up to 58F. Got almost immediate feedback in ST (below). I didn’t even realize the integration was working just fine because the thermostat was holding a steady 55F in the Living Room. The system does not reporting a value via polling, but via a change in measured value. This is similar to my Aeotec Multisensor 6 reading Lux and temperature. Only changes in value are reported. Note below that the room temperature went up a tiny fraction of a second before the setpoint change was reported.
I have the square. (two of them) As long as it doesn’t lose Wifi, which it does about once a month, it works fine with smarththings. If I just leave it alone, it will reconnect eventually.