I just had my sprinkler guy out for blowing out the lines to winterize. As we ran the zones with air I received a Low-Flow Detected email and app notification for each zone. I also found it a little harder than expected to run the zones for a manual 2 minute then 1 minute cycle each. It seems to me that Rachio could add a Winterizing mode that lets you easily cycle through the zones and mutes any WFM related warnings.
I mean, I am winterizing, I know that there is no water flowing while the zone is running! Duh, Rachio!