It all depends on what you’re using it for and how many false alarms/triggers you’re willing to deal with. If you want zero lag and zero false alarms when using multiple presence sensors then it’s going to pretty tough.
SmartThings isn’t quite to the point that it functions like the doors on Star Trek (how the doors knew that it was someone actually wanting to go through the door and not just walking down the hall always fascinated me. how did they know? someone standing in the same exact spot doesn’t make the door open but it does when they wanna go in.)
With ST mobile presence period, it’s going to be tough for a lot of folks. I’m glad I’m one of the fortunate in that minority who have never had any ( very minor) issues with GPS whether direct with the ST app or using webCoRE for mobile presence. Maybe someday this functionality for all will be trivial to configure and have it actually work for one phone or multiples in a household.
I used a delay because my road backs up on itself when I leave my house and I didn’t want to disarm the system as I was driving away from home. As a fix I’ve reduced the zone around my house slightly so it shouldn’t catch me as I leave. I’ve also taken off the delay.
Just don’t make the perimeter (Geofence circle) too small. I know this to be one of the many hundred of different issues that cause some phones / ST to not report correctly for Presence.
