@Manofice and @seattle505,
I have 4 of the original arrival sensors, and even though they do eat batteries, they work very well for me.
I have one in each car, usually inside the sunglasses holder, or another small compartment (not the center console). 2 cars sit outside, and the other 2 in a garage. I have no issues with ST recognizing when they come and go.
I would say for sure the system should disarm before any sensor trips. While I don’t us ST’s security feature as my primary security system, I do use it on occasion and it worked pretty well for me.
To test out @seattle505’s use case when I first read this post today, I created a Routine to disarm when my wife’s car got home. She was out of the house, so this was a great opportunity to see if this worked as expected. As soon as I heard the garage door open I started to see when the arrival sensor was picked up by ST, and when it disarmed. Here are the events in the order they happened:
Garage door opens:
Arrival sensor arrived:
Security turned off (disarmed):
Wife opens the door (and no alarm screamed at her):
Here are the notifications in the phone app: (I have no idea why they showed up 3 times, or why you see null in the messages)
I didn’t test with more than one arrival sensor, but I did check just now how that would work. When selecting which arrival sensors, the solution says “Any of these people”. I think that would imply that both your wife and son don’t have to be home to disarm it.