Very cool. I own a couple 3 pu basses, a '63 Burns of London Vista Sonic med scale, and an ESP/Grass Roots Bass IV. The Bass IV can run with all 3 pu's together, or any combination with individual pu on-off switches. So 'all off' is like a kill switch, of which I am a fan. The Vista Sonic's; Wild Dog / Treble / Bass / Contra Bass is combination oriented ...
Wild Dog was wired out of phase and sorta useless. I reversed the wires and it made it sound like a Jazz. (B & Mid-pu's)
Treble is only B-pu,
Bass is only Mid-pu (like a single coil P) and
Contra Bass is only N-pu. (overly bassy) The Bass IV is a very versatile bass where as the Vista Sonic is less so. (as in, I usually only use a couple of the choices) I could see your set-up being good but if it were mine I'd include a 3-way pu switch like on my Bass IV to isolate or add pu's quickly w/o losing settings.
The Bass IV has one more switch (lowest in line) which by-passes the V/T pots adding a clean boost at the flick of a switch. Very cool/easy mod that could be added to any multi-pu bass.
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