A friend of mine just got an ubertar pickup fitted, I think he's looking at it in a studio context as a stunt effect (like panning strings across stereo left to right) rather than a bread and butter solid sound. I always think of the Paul Jackson Head Hunters recordings (bass called geraldene iirc) where the pickup was output per string, recorded individually, so yeah, kind of niche - I remember as a kid in my dads studio a session guy came in with a paisley tele which has stereo outs and a pan knob per string so he could use two amps, even then I was a bit like 'huh?'. It was a great look though, cowboy shirt, boots and hat with the paisley tele and matched fender amps.
Amazing work! I love seeing your builds