I'm not sure what Leo was going for, beyond squeezing more tonal options from passive circuits and trying to make a floating trem.
I think that's exactly what he was trying to do. And to design a body better suited for playing sitting down, which worked very well for the Jazz Bass.
My 6-string is a Tele, I also don't like the Jazzmaster's darker tone, But that's down to individual taste. The "dark circuit" was his understanding of jazz guitar tone, he probably wanted to approximate a jazz box, neck pickup, tone dialed back kind of sound.
There were times when some guitarists wanted as many knobs and switches. Even well into the 80s. I used to mod Strats with tons of switches, everybody wanted them back then.
![](https://media.gettyimages.com/id/91001496/photo/les-holroyd-of-english-rock-group-barclay-james-harvest-playing-a-double-necked-guitar-bass-at.jpg?s=612x612&w=gi&k=20&c=bIIW_C6VWpY6rKFGSUeUekTTey-UfpVUW56TBwX7uXI=)
![](https://www.myrareguitars.com/guitar-pictures/jack-casady-guild-starfire-bass-guitar.jpg)