I think Shadowcastaz has a Q-tuner in one of the basses he built, IIRC...
Can't wait to hear the Decade, Barkless! Looks great! Those q-tuners are 'spensive too. I was looking at one for my scroll bass, but ended up using a Pitbull - which I think offered more of the tonal character I wanted there (and actually cost about the same too - what is it with pickup prices?). I guess it was worth it, though, as it made the bass useable. It came to me with some awful scooped-mid sounding pickup in there when I bought it.