Why do you have cue switches in both the effects and crossfader section?
The cueing in the effect section is the 100% wet cueing so you can test effects through the headphones before moving the wet/dry slider from dry to wet. The cue switches in the crossfader section are PFL (pre-fader level) cues so you can listen to audio before bringing up volume on the CH1 and CH2 line faders.