Swapping bridge pickup in Cutlass SSS

Just took receipt of my new Cutlass and boy is it an exquisite guitar (routed for an HSS configuration too, which is neat and adds to the versatility). Now, I used it with the loud band last night and thought for some upcoming shows I’d the bridge pickup for a JB Jr. I have on hand.

I contacted support and they said it wouldn’t harm the electronics to hook it up, and the hot and ground is clearly labeled on the circuit board, but there’s also a third wire coming from the EB pickups that goes to a point reading “PHA.” Now, I’m wondering if anyone here has swapped their pickups in the Cutlass, and how I should go about wiring it.

The JB Jr. is a four-conductor, so I could wire it as a normal humbucker with the two coil leads soldered and taped, but I was wondering if that that PHA has something to do with the 4th position coil sound. Not entirely sure and neither was customer service.

TL;DR – How do I wire a JB Jr. (temporarily) in the bridge position of the Cutlass?

Attached is the wiring diagram.

Attached Thumbnails