FWIW, I automate the heck out of my garage door and door locks. I use Combined Presence to combine GPS presence with WiFi presence and I've never had an issue. The biggest security risk is a false arrival, but GPS won't falsely mark me as home if I'm not close and WiFi won't say I'm connected at home if I'm not.
I do have an automation that warns me if the door isn't locked or garage is open if we're both away for 10 minutes, but the only time I get notified is if I run to the hardware store and leave the back door open on a nice day.
