Dual coils capable of hum free two way coil split?

Those are quad coils, not dual coils. They’re essentially two split coil pickups next to each other. So search for quad coils. I think Nordstrand and Delano make them, likely others too...

 

Barts are pretty much it.

Delano makes them but they're wired for "P", All Coils, and "Reverse P". No front and back per se.
Edit: They also make a double J with four coils that will do front/both/back.
DELANO DJC 5 HE/M2

Some companies are open to custom options. Maybe Nordstrand. I contacted Seymour Duncan once about this but no response.

 

Delano SBC's are my favorite pickups to date. Like a Bart with more extended highs.

 

I'm curious as well.

The only graphite bass I've tried was a modulus with Barts. Creamy but too dark for my tastes. Probably the original series. All very subjective. I like the Delano's because they're clear but never harsh. Easy to warm them up with the tone knob.

Big Singles in my Ibanez are a bit harder to tame on top while still keeping high end details. Mid heavy pickups.

Nordstrand Dual Coils sounded much more refined in the MTD I heard them in. They would do well if they can make them into quad coils.

 

How about Sims quad pickup?

 

I think Bartolini might make what you want. One thing to note with 5 string hum cancellers - the in line versions generally have one short coil (covering 2 strings) and one long coil (covering 3). As such, they typically have less hum in "single coil" mode (about 1/5th that of a 5 string single coil - 3 minus 2 is 1), but not zero hum. The Bart 5 string J inline hum cancellers do the opposite thing on bridge and neck, so when BOTH are operating, you get zero noise, but with just one pickup, you get reduced (but not zero) noise.

If you look at 5 string P pickups, a lot of them have an awkward looking pickup half - the half that covers 2 strings is as large as the one covering 3. Usually that means they have a dummy pole in there, so the thing is balanced, and noise free. In line hum cancellers don't have the space to do that.

 

Don't let me put words in your mouth.
"I want humbuckers", You, 06/30/2020

 

Yeah, I'm just messing around.
Have you looked at the split J from Fralin? Or others?

 

Yeah, Nordy makes them. They're pretty bad too.

 

Don't know what pickup shape you want, but Nordstrand makes a MM shaped 'Big Splitman 5'. It is basically 2 big split pickups stuffed into a MM size shell. Tremendous pickup and will do what you want. Two of those will be some serious coin, but if you like Nordstrand products you will be in heaven. I have delano pickups in one of my 4 string Mayones basses and they pair well with my Mike Pope Pre so that is a good contender too. IMO they are brighter so your concerns with the graphite neck may have merit.

I have enjoyed MM basses with the humbucker splitting similar to what you describe - inners, outers, etc. I have built parts basses with big quad coils. Truth told if building another one tomorrow I would use a set of BC sized big splits and a pre with a blend pot. They are great pickups. The coil switching is more of a gimmic and complication than a useful tool to me. Most times when people are discussing MM HH coil options, the favorite positions are inner coils and all coils. Everything else sounds weird to me and apparently to some others too. I have a MM HH Gamechanger that allows you to program ANY combination of coils, series, parallel, etc. Literally hundreds of different possible combinations. Sounds best with inners only sent parallel. Just something to think about.