If I were in your shoes, I would play as normal using the s4, the clubs mixer won’t make any difference, unless it was your home monitors that are playing up.
Always have a song ready to play either in a cdj or your phone, MP3 player etc, plugged into a spare channel on clubs mixer if you do get any problems. Then the music will stop for only a split second.
If you do get the audio glitches, maybe after 1 1/2 hours change to a cd, phone short mix you can play and restart laptop then go back to s4, do this until end of your set, (not the best but saves the music stopping)
Make sure your wifi is turned off. Any anti virus programmes etc, and this can interfere with the audio.
Have you changed the latency in traktor setting????