UR44C has USB3.0 port. In the manual it is called USB 3.1 gen 1 port, which is the same as USB 3.0.
I have connected it to USB 3.0 port of the computer. If I choose USB power, the ring around Output knob keeps flashing and the interface does not work. After connecting the supplied 12v power cord and choosing it as power source the blinking stops and the interface works perfectly. (Win 10, Cubase)
So everything is cool. But as I formerly wrote, at least some basic EQ plugin for the output monitoring signal would make this kind of unit even better, as it gets used as a standard audio card also. A little software update perhaps?