Omnistat Zigbee or Nest thermostat for radiant floor control

Hi All,
I am looking to put together a home automation system that can control, among other things, our 4-zone radiant flooring system as well as our 2-stage furnace and central air conditioner.

You may be aware that radiant floor thermostats behave a little bit differently from thermostats meant for forced air systems. Our radiant flooring system uses hot water piped through a concrete slab. Because the concrete has thermal mass, it has “thermal inertia” and “thermal lag” when actively heated. This means that a normal thermostat would overshoot the setpoint temperature by several degrees.

More and more thermostats are incorporating logic for radiant heating, but I haven’t found a model that integrates Z-Wave. If I am wrong on that, please let me know.

I have found that the Nest thermostats support radiant floors, and that there is an unofficial way to add Nest support to SmartThings, but I would be concerned about it working correctly with potentially 5 thermostats at once.

The other potential solution is the HAI/Leviton Omnistat with Zigbee support. SmartThings supports Zigbee, but I don’t know if it would support this thermostat model. Does anyone have any experience or insights into this?

I am trying to connect to smartthings app, latest version, and it doesn’t show up as one of their thermostat options…