Adjustable pole pickups.
I had this issue in extreme with a CIJ FL Jazz. I tried new PUs, bridge adjustments, different gauge strings and nothing worked. Then a set of Dimarzio JP 123s allowed for individual pole adjustment and problem solved. My Alesis rack-mount compressor has a long row of gain/reduction LEDs that allow for very sensitive string to string output comparison and I've got them spot on.
The opinion of most musicians I have met is that the music industry sucks. This is because the music industry sucks. - Robert Fripp