Posting to keep this topic alive. The paranoia expressed in some of these comments (of questionable validity) could be easily mitigated by making it a paid feature only available for activation within the Rachio app. Liability for damage could be eliminated by wrapping the feature in whatever warnings the lawyers think is a good idea.
This feature would be of great value to me. I have five zones and I know where three valves are buried. Locations of the other two are a complete mystery!