My experience with a tilt/vibration sensor on a Velux tilt window was at best doubtful. Your best bet is to act on the tilt and or vibration alarm, which proved more accurate than the tilt angle itself. I found the latter to be close to useless.
A door sensor will probably be way more accurate, but the parts need to be out of the way of the newspapers and other big deliveries so they won’t be pushed off by the postman.
