Do EMGs have their own switch now? I've had EMGs before, just the 85, 60 and 81, but they only needed their own stereo jack (as well as their own 25k pots). The standard switch was fine on whatever guitars I had them in.
The 89s have the splitting capabilities (basically an 85 with the single coil mode of the SA.) Usually for splitting, you'd either use a mini switch or push/pull pot, but I figured there might be some way to get the splits with the PRS 5-way rotary, or maybe even add push/pull to the volume and/or tone controls. I'm not good with wiring, though, so I'd have to take it in to someone if I decide to swap out the Duncan Pearly Gates set that's in it now.