[Cuki79]

Originally Posted by jparis51

Obviously bypassing the sound hole controls also means bypassing the onboard preamp

Not necessarly... I think you don't have to do what Peter Z suggested which is getting rid of the internal preamp.

Most preamp soundhole control are just
* passive filter like the tone pot on a Strat or a Les Paul
* passive attenuator (just a poteniometer making a voltage divider)

Schatten Design sells generic thumbwheel you can configure into any kind of combination of control. They work for all pickup preamps.

Schatten T-1 thumbwheel:


Schatten T-2 thumbwheel:
https://www.stewmac.com/globalassets...configurations

Unless you have an advanced preamp (Aura or Blend), if you know someone with a Multimeter and a small background in electronics, she/He could probably help you out and bypass the thumbwheel.

NOTA BENE: In your case the thumbwheel control is likely to be POST PREAMP/BUFFER.
Here is for example the signal chain inside a PZ-Deluxe from Radial Eng

One can see clearly the preamp comes first and then volume & tone.

My 2 cents,
Cuki