UR 44C - phone outputs option

I have here my UR44C and I was wondering if there is a way to send a different audio stream to the phone outputs. Per default they mirror the main out (ch 1-2).
Is there a piece of software that controls this? Like a setup interface?
I have on my computer (Mac-os) the ‘dspMixFx’ but I guess that is only for iOS devices…

No, it is not possible. You can use outputs 3 and 4.