The only place I remember seeing Outer Coils in Series is this
diagram guitar electronics published over 20 years ago. It's odd they say its the PRS Rotary sounds from that time - this was before PRS moved to blades. I had access to the PRS line and service diagrams then. It was Inner Coils in Series 100%. PRS wiring has a lot more variants now that I'm not up to speed on.
I've only ever done Inner Coils in series on Vintage to mildly hotter PAF types under 9K. With clean to overdrive its a little crisper than both humbuckers in parallel the middle position, but still softer treble than if you had an actual series humbucker in the middle position.
There's plenty of threads here about Inner vs Outer splits and parallel combos and comments from Triple Shot users. The biggest thing is splitting the bridge HB to the outer coil can be weak and thin because its so close to the bridge itself.
Well here's the outer coil version. Enjoy!