by Adamadamadam » Tue May 17, 2016 6:23 pm
Since it's a two conductor hb, anything position that engages the neck pu (or bridge, but I'm assuming it's an hb in the neck and sc in the bridge) should use the whole hb. So the BL wiring should be HB, HB & SC, SC, HB & SC oop, bass cut.
If you wired it up (four conductor) like a standard strat then yes, pos 4 would be the full humbucker. But there are also a bunch of alternative strat wirings out there. My favorite, and granted it doesn't use a 5 way switch, is doing the nashville tele thing where you can blend in the middle pickup. If you go that route you should use the four-way tele setup, that gives you the options of b&n both in parallel and series.