The Kontrol S4 MK2 is by far the best DJ controller I use. It's fast and intuitive and lets me play around without a lot of work. The one issue I face while doing prep mixes is that it's cumbersome to add my first beat grid marker and fix autogain - particularly while I'm mixing (and recording) live. These settings traditionally require jumping to my trackpad to change UI views and make adjustments.
Turns out Native Instrument's new Kontrol S4 MK2 has a hidden gem in the new update: Booth Out!
According to the new User Manual, on the back of the S4 MK2 are RCAs for Main Out and 1/4 for Booth Out. There's a recessed Booth Volume knob next to the 1/4 outputs. Next to that knob is a switch for Booth / Main. If set to MAIN the 1/4 outputs will output same as RCA. If the switch is set to BOOTH, the 1/4 output volume only uses the back Booth Volume knob and is independent from the Main Volume knob.
Since most pros don't fiddle with main out volume, the easy work-around is to swap roles and use 1/4 for main out and RCA for booth. You can set a good main-out level using the back knob, and use the convenient main volume knob for your booth.
Traktor's cue points are a handy way for DJs to jump around and keep track of different events within a track. For example, the guys at DJ Tech Tools use cue points to highlight the first beat, the best start point, and vocal cues (as well as trigger points for sample loops).
Myself, I use cue points in a more traditional, yet universal manner. I've been using a technique I call the Countdown Method for about a year now. Basically, cues are used in reverse sequence (as in 3-2-1 go!) to coordinate mix-in and mix-out points.