Reply to alt. functions for x-fader

hey all
i've got an x-session pro and an x1. i use the xsession to control 4 decks and i don't use the xfader - i just use the volume faders. also i use sync, playing electro and house so i'm not adjusting the pitch too often.

i'm trying out a mapping where i use the x-fader to contol the pitch of the master/focus deck. so when they're all synced, i can adjust the tempo of all decks for a new track that is faster or slower. hope this makes sense so far.

then i set one of my headphone cue buttons on the xsession to tab through decks selecting master/focus. with the tempo % at 35, i can adjust the tempo for effect and slow a 120 bpm track to 100 or so and then bring in a new track that is 100 bpm.

as i write this i'm believeing i don't even need to have a button to tab through master/focus. if they are all synced, i could adjust one and they'll all change.

is there a way to control the pitch of the master deck? am i looking at finally learning how to do a modifier to have that kind of control?

anyone else use the x-fader for an alternate control purpose that is super useful?