Unless OP has VERY particular tastes, it's probably one of those things you do when you have more positions than you know what to do with.To me, this one is rather uncommon. How did you decide on neck hum and bridge single as a combination?
View attachment 144177
It's what happened with my Oni. I wanted full hum and single coil plus a couple of parallel positions, and ended up with this monstrosity
![Oni_Essi-8_Freeway_Diagram.png Oni_Essi-8_Freeway_Diagram.png](https://www.sevenstring.org/data/attachments/123/123706-f203305b1141080625444d15fcfd0eb7.jpg)
I also have full hum+single coil, but it's all wired in parallel. From what I can tell, adding different coils in parallel is almost like adding/removing EQ corresponding to the location of each coil, plus a few dynamic characteristics like levels of attack, etc. A bit more predictable than a what it would sound like wired in series. Like if I am in position 4 (bridge in parallel) but wanted a slight bit more bass/creaminess to the tone, I'll go all Initial D on that switch and jump to position 7.
It's not like I immediately know which combination I want to use, but if I am not happy with a particular sound, I'll play with the switch to see if I have anything that helps before I adjust any amp or pedal settings.