NGD Silo + wiring

I finally have my first EBMM, a Silo. Thicker neck than anticipated, but comfortable. Love the (rosewood) fretboard. Very smooth playing. I need to get used to the ‘smaller’ size.
I’m thinking of adding an option to split the humbuckers using a P/P or mini toggle, and I took a look under the hood. I am told that it are not the original elements, although a previous owner put back the same type in a later stage. Not entirely convinced of the virtual PAFs, particularly the bridge. The middle position is loud, while positions 2 and 4 are disproportinoally quiet and position 2 is very shrill.

So I had a look, and apparently it has a super switch (is this common in Silos?). First time I laid my eyes on one. The wiring is not what I expected.
position 1 = bridge
2 = (full) bridge + SC
3 = both humbuckers (full)
4 = single coil
5 = neck

Could it be that the bridge and SC are out of phase? Hence the very silent and trebly output?

I do like the sound of both humbuckers together, although I want to split them (single coils), have an autosplit in positions 2 and 4, and also have the possibility to use the outer coils of both humbuckers together (tele style).
Can I use a toggle switch to select either one of the ‘blades/sides/poles’ of the super switch? I guess I need to connect the commons to the mini toggle?
One side would then be the ‘default’ HSH with autosplit in positions 2 and 4, while split humbuckers each, split outer coils together, and 2 humbuckers in parallel would be wired on the second side.
Does this make any sense?

In addition, how do you remove the pickguard without having to restring the guitar each time?

Thanks!:)