I also don’t have a AK but I would assume if you want FX applied to an external source you can route one track through the mains with FX. My understanding was if you route the remaining tracks out the additional outs they will be dry with no FX.

Not sure if this is what was trying to be accomplished. Also Overbridge should provide much more flexibility with this since over USB you will have all four dry tracks plus a fifth FX only track.