If you have a humbucker and split the coils, you're not going to hear much differance between the two coils when split...Perhaps in a studio situation, but in your room or on stage? It's not worth it. Just split the north on the neck and the south on the bridge.
There are lots of cool things you can do with guitar electronics, but in reality - most people don't use half of it...and the other half all sounds the same
That's an exageration...but it's common to want to put as many options as possible into a guitar.
I am currently working on a Tele Thinline for a customer that was sick of it's "thin & twangy" sound.. So we're putting a SD Seymour Duncan Pearly Gates in the Neck, a Tele Little '59 in the bridge and giving each their own volume. Now being a big Tele Fan, I wanted him to be able to get that sound back..so the knobs will be push/pull to split the coils, and the tone knob can switch from parallel to series (the pickups, not the coils) for a "turbo boost" when needed. That's about as much as I'd throw into a guitar... Jimmy Page's guitar tech once went on and on about the crazy electronics he had in his LP...then finished the interview by saying that no one could tell the differance..ha..