Yeah, this is kinda what I thought it would be like. In other words it’s entirely possible to give a “false positive” That is… the door is close enough that the sensor registers closed, but the door isn’t closed enough that the latch isn’t in the strike plate… meaning someone could push the door and it would open.
I thought about mounting the sensor between my screen door and my main door… this would probably allow me to separate the sensor enough that it’s only when the door is fully closed that it would be close enough to trip the sensor. The major downside is that the sensor is “outside” and someone trying to break in could relatively easily fool the sensor.
Of course, even a contact sensor could be fooled by a door that is almost all the way, but not quite perfect. The only way to know for sure would be to have a sensor inside the strike plate that senses if the latch is inside the strike plate or not. I don’t think my Kwikset has the ability to know if the latch is all the way extended or not.