In order to address the shortage of hexaphonic guitars that can be used with single-string processing, I'm developing a family of commercially available guitars that are retrofitted with the best hexaphonic pickup on the market: Cycfi Research's Nu Multi.
I'm starting with a Strandberg Boden Classic 6, because the Strat-style pickguard makes the conversion easier.
A custom pickguard and custom jack plate are required; I will also include a set of EMG active single coil pickups to achieve the lowest noise floor possible.
Why not GK-3, you ask? Because the GK-3 pickup sounds terrible as an audio source! It was designed for pitch detection primarily and has a very poor frequency response, which makes it a poor choice as a source for effects processing or subtractive synthesis. Essentially, there is very little tonal (harmonic) character to work with.
SynQuaNon will address this GK-3 deficiency in 2021 with a module that will improve the tonality of the pickup; however, as they say: "garbage in, garbage out"!
I don't hate GK pickups, I just know they work best with BOSS/Roland guitar synths (I own 7 of them!)