Hey guys, I'm planning on rewiring my guitar over the summer break. I just want to know if the following is possible on an Ibanez S guitar with HSH configuration, before I research my ass off in order to figure out how to do it:

-2 volume (one for the bridge, one for the neck and single coil)
-1 master tone
-coil split both humbuckers

I wanna avoid drilling a hole on the guitar (although there seems to be a perfect space for another knob between the two knobs already there). I'm thinking maybe use concentric knobs? They don't seem very common on guitars, does anyone have any experience with them?
Yes, it's possible.

You can use a pull-out knob to control the coil splitting, or a 5-way superswitch (might not fit in an "S"s thin body--I had to route down to about 1/16" of wood left in the bottom of my Squier Affinity Strat's control cavity to fit it in there.

I haven't seen a push-pull concentric knob, and it would be sporty to control coil splitting on 2 pickups with one push-pull (it might be easy, but the method I'm thinking of might not work; besides you may want one split and the other not, like you can do on a Fender Big Apple).

My Squier is set up with 2 volumes and 2 tones (using concentric for the tones). I control my coil tapping & parallel vs. series with a Fender S-1 switch in the neck volume knob. No reason you couldn't use the concentric pot for volume and have a master tone with the other pot.

I needed the S-1 so I could have the parallel vs series options. If all you want is coil splitting, you can certainly do that with the 5-way. My objective was to have a Strat with a hot HH combination, done up like an MIA Deluxe (or a Big Apple) S-1 "stealth" switching, but also with a volume and a tone for each pup, and kill-switch capability.

Here's a thread where you can track the thought process that it took to get there. If anyone else had done something like that before, then I couldn't find anything about it on the internet during the year or so I was researching it. https://www.ultimate-guitar.com/forum/showthread.php?t=1149482