For a successful arm of the system, there is feedback to the server, and then to the app. I know for two reasons. First, I’ve seen the string the server returns for a successful arm, in documented Blink API commands on github, and second, on more than one occasion, I have had a warning report back that the system failed to arm. For example, “Garage failed to arm.”
How that relates to the option to individually set cameras to detect motion, blue man, I could only guess that it has the same feedback mechanism, but cannot confirm. Can’t see why it wouldn’t.
Probably doesn’t draw significant battery power, because it isn’t WiFi, it is low frequency radio, which Blink refer to in their documentation as LFR, and the data required for such an instruction would be a super short burst of just a few bytes. I can almost guess how long, less than a second, because I sometimes hear it via my wireless headphones. Indeed it does this regularly anyway, once in a while. Again, I could guess that this is just to report current status. Temp, battery voltage, camera operational, etc, etc. It must do this, because occasionally I get reports that say similar to, ‘Drive camera offline’, which if it just slept, all the time, during inactivity, there would be no way to know.
Actually, I looked in the app, when I first looked at this thread and about thirty minutes ago there had been an update to the temp details, etc, at 21.36. I just now looked again, and there was a further update at 22.07. So looks like it checks every thirty minutes, to make sure all is well.