Anson Funderburgh...the middle pickup man!
I also have a guitar with 3 humbuckers, 3 P90s, one with 1 P90 in the middle, and an old Kay with a single Hershey bar in the middle.
Crank the treble on the amp and use the guitar tone knobs to dial up what you need!
Count me in on strats! The only guitars I don't like them in are teles, and that's just because I think teles with those strat style single coil middle pickups ugly. If I'm not inspired to pick up a guitar, I don't care what it sounds like.
I guess I'm the outlier. Never could bond with this this sound. I would always take position #4 over #3, but otherwise spend most of time with the neck, and/or a swapped out bridge (twangbanger) pickup.