You can implement a backup router through ICI yes. For example, you can have your normal network running on PANID ABC1. On the side, you have a border router running on PANID ABC2 and just waiting there with no connections. Then you create an event-handler that if devices on the network lose connectivity for a while, then they switch their PANID to ABC2. Then they would go and connect to the 2nd border router automatically.
Last Update: January 24, 2020