Just updating this post on behalf of @SuperSmith (replied via email with the following):
Commercial office building with drip irrigation only. I could run 3 to 4 zones at the same time if the controller had that capability. I have one commercial property that has 64 zones and I have to run 7 at a time just so I can get everything water in the same day during my restricted water times. I would like to run 3-4 zones at a time.
The Iro is capable of running 2 valves at a time; however if your system has a master valve, it should be considered one of the two valves.