To make routing easier for beginners and still cover most requirements, it would be sufficient to be able to switch on a MIX to the MAIN for OUTs 1-6 (see the simpler Block diagram below).
For the USB-Routing: Besides of recording, you mostly will use the CQ as In- and Output for a DAW or use the USB path for inserts with plugins on a computer but seldom mix this both. Therefore, the global recording source point is not much of a disadvantage.
