I use @doug's Presence Governor to set the state of a virtual presence sensor.
I use Mode Manager to set the mode based on the state of the virtual presence sensor, and HSM is set based on the mode.
It works flawlessly. The big advantage of Presence Governor over other similar apps is that it permits setting configurable thresholds for presence detection. If you're using Combined Presence or something else, give Presence Governor a shot - it's incredibly reliable.
