I have a Westone Thunder III (Issue 2) that has phase on the push/pull Volume control.
I find the Out-Of-Phase much more 'useable' on a bass than on guitar.
Pulling the switch plus adding a bit of bass boost makes for a very punchy tone.
The controls on the above are, from nearest the strings:
Vol push/pull phase
Passive treble roll-off
Active tone - bass boost anti-clockwise from detente, mids boost clockwise
Three position tone selector.
Top mini-switch is parallel/serial on both pickups (neck is a P in a rectangular shell, bridge is a 2 spool humbucker)
Bottom mini is active/passive.
18 volt electrics.
Also beautifully built - I think it's an '86.