Is there way to map Audio Deck Channel Output change in Traktor?

I am using turntables/DVS with Traktor.

I have it set up right now to control all 4 decks with the tables - I press a button on my controller and can switch from internal/relative playback for A/C; B/D. This works great, I use A + B for track playback mainly and C+D for remix decks scratching.

What would be ideal but I don't know if it is possible would be to be able to map a button on a controller to switch a deck's out put to my mixer's 3rd line. If there were issues with audio loss switching over I could simply duplicate deck A to B say, and the Deck B would be on 3rd line and do mixer channel fade to switch to mixer channel 3. I need the decks set up standard on my mixers 1-2 channels; but it would be nice to be able to temp route a deck playing a beat to mixer's 3rd channel and be able to scratch on both 1-2 mixer channels. Is this possible at all?

Also - on a mapping topic - I just got a Novation Nocturne to map fx control with traktor - it mapped fine, however on the button pushes for the fx I am getting the double push thing.. have to push it twice each time to register on/off - which also throws back the led feedback. There don't seem to be any setting in the control setup that I can mess with for this - it is a button set to toggle - and it won't let me choose anything but button.

Thanks