Good point on the S1 switch on the P, but I don't think they ever did that on a 5 string, which breaks the model, and maybe I should be extra clear here, is I'm talking just about 5 strings.
You can do more with 4 string pickups because of the symmetry, which is why I brought the whole thing up... this is a specific function of the asymmetry of a 5 string split coil humbucker.
Also, I was looking specifically at the 5 string UJ (sorry, again, shoulda' been more specific), which is 2 conductor, and I'm sure it's for that reason.