yes the routing matrix would be really useful
1) repatch the output from the usb or SD to different channels
2) move one input to another channel during live
3) use the output aux jack to get signal from other sources like: -> get main l/r, duplicate the phone output to an aux, etc, temporarily patch an aux from another source (I use in ear monitors and I also make sound and during soundcheck I usually switch on the behringer my aux to the main l/r or to the monitor bus)