You can stream directly to the individual outputs of Konnekt from within your audio host application, so you can always create a separate mix for each of the outputs from within your audio host application, if it is able to do so.
Most audio host applications have quite extensive support for individual submixes. For example: if you're a DJ, you'd perhaps like to have a seperate cue mix independently from your main mix. That's possible.
With the internal direct monitor mixer in Konnekt, you can create a separate submix by using the sends from each channel and assign that submix to, say, outputs 3-4 or digital. On the other hand, it's not possible to do complete mixes for each of the two sets of stereo outputs within the Konnekt mixer. The Konnekt 24D mixer does not feature a routing grid as such, though it is possible to assign the SEND knob -- by default set up for sending to the Fabrik R -- to control what is being sent to outputs 3+4, the S/PDIF or the ADAT/TOS outputs.