They are useful as powerful Zigbee repeaters, I have several in my mesh just to route signal. They can use the "Device" driver built in Hubitat. You have to setup some parameters using XCTU to get them to join. If you look at the everything Xbee thread people have use them as presence sensors in their cars, by loading some code on the Xbee.
They are also great at mapping your complete Zigbee mesh.
See the link below:
