@plainsane That seems like a different ballpark. I’d like to have one sensor per zone. But I guess it would be expandable to as many as you want, so long as you have wireless reach. The limit with my proposed approach is the range of the Bluetooth LE in the Xiaomi sensors (since they need to reach the wall-powered Bluetooth/Wifi Bridge). The GreenThumb sensors have built-in wifi which would give a bigger range (but the battery life is only a few months).
I guess I’m not sure what your point is?
The key issue is that Rachio doesn’t have the ability to use soil moisture data, regardless of how many sensors you have.