Thing is really simple actually. In a humbucker the two coils are wired in series. On a typical strat, or a dual P90 guitar, the middle positions where two single coil pickups are active are wired in parallel. Now in the case of the dual P90 guitar, if you have a switch to change the middle from the classic parallel to series you are wiring the two coils together like a humbucker would be. Thing is those two coils are much fatter, with stronger magnets. I mean they each can keep up with a humbucker, but now the two together function as one. Thatīs why I call it a super humbucker.
On my Stockholm bridge, Supermassive neck LP that is one of my absolute favorite positions. Balsier and more a tad more humbucker like rounded than the bridge solo, so amazing for riffing, and for solos it is also great and agressive. Itīs more of an alternative bridge tone, where as the classic wiring is more of an alternative neck tone.
Hope that is understandable. Wiring is initially a bit hard to grasp, I know, but in essence it is astonishingly simple I think.
Canīt comment on the CS neck idea though, gotta leave that to Chris and others.