Best practices for startMonitoringForRegion (ios)

I need to monitor several estimote beacons in the background - 2 in a san francisco office and 2 in a mountain view office.

Is it recommended to call startMonitoringForRegion four times, once for each beacon? Or is there a better approach?

Also, is it ok to call startMonitoringForRegion several times for the same beacon, or should this be avoided?

What's the approx upper limit of the number of beacons that can be monitored with startMonitoringForRegion?

Please check these two articles about it:

Hope it helps!