To finally route every engine to its own output, go into Kontakt's instrument
editing mode by clicking the wrench icon:
Then scroll down until you'll see the „Instrument Buses" section:
If necessary, click on the triangle to expand the section:
You'll see the Instrument Buses 1-4 which correspond to the Atheos engines (#1
Sampler, #2 Time Machine, #3 Tone Machine and #4 Noise).