I use the Ring contact sensors to turn on and off lights in pantry, closets, etc and the wait is negligible...the lights turn on I would say less than a second. I got the Ring Gen2 sensors on the recommendation of @bcopeland.....My Favorite Devices (Updated)
Note that the Ring contact sensors Gen2 can only be used on a C7 because it requires S2 security......Support for Ring Alarm Contact Sensor V2?