Thanks for the great suggestions!
The pickup should be more or less in the traditional sweet spot; it's a custom job with a medium scale neck... we'll see what I get from the factory! If it's close enough, I'll just leave it, if it's way off I may need to do some routing and filling.
I had wondered about the single coils being too close to really be distinctive. It would certainly simplify things considerably to leave one of the coils out.
Simon is correct, this pickup just has the 4 wires to work with, so I don't think doing the P-bass split is an option, unfortunately.
I need to do some investigation into adding a cap between the pickups in series, that sounds very interesting. I have a feeling this is gonna send me down a rabbit hole of all sorts of weird mods haha. Gotta fill the time waiting for the bass to ship somehow!