If you want to beat match using only headphones you might want to look into split cue, theres a rough description of how to do it in my post here: Split Cue in Traktor
If you don’t go for split cue you might still want to look into making the channel cue also control the cue/master mix knob so that when any/both tracks are cued you hear the cue signal and when nothing is cued it automatically goes back to playing the master. This is a fairly simple mapping but will need to use a modifier.