Okay, I went with a leap -
Nordstrand Big Splits, wired passive. Thomastik-Infeld Jazz Flats. Holy Mary, this thing sounds huge!

It's an absolute punchy toneful warm monster, and I can't wait to gig with it tomorrow!
It's got more output than any passive I've ever seen - I have to dial things way back. There's plenty of nice tones to be had, and I really like the bridge solo, which is rare for me.
at 5 neck and 7 bridge, with the tone pot rolled way down (almost closed), it's just the tone I was describing above. There's more growl to the mids than I thought I wanted, but that's a good thing - I think this thing will sit solid in a mix but never disappear.
I did have to use a Dremel and sanding head to take off 1 or 2 mm from each side of the rout (3.95" pickup was just a hair too wide). No big deal. It does also leave a gap in the 1.25" dimension, so I may do some custom rings.
If I get a chance this weekend I'll try to post some sound clips. I've been going through an ART MPA Gold with a vintage tube, direct into a power amp and a 410. This has no tone control except what's on the bass, and what I'm getting is very useful no matter how I dial it in.
That said, it's easy to overpower and get crispy. The stock harness has Alpha 500k pots in VVT setup. I'll think I'll start with the tone pot and go 250k - is that a good place to start? I'm not sure which ones are ideal to swap out. I usually go all 250's, but I like the voicing of the pickups themselves, I just want a more useful range of the tone control than the last 25%.
Any suggestions for passive pot matchups?