Actually it can change the resonant peak and add small +dB changes to frequencies lower than the original resonance leading to a slight low-mid boost at the fully CCW position. This is a well documented phenomenon already discussed in this thread. It's obviously nothing like an active bass boost control.
I don't understand any of this too well. However, the resonant peak is the product of the inductance of the pickup coils interacting with the other controls? If so, could you use a dummy P bass coil (no magnet), with a capacitor in parallel, to add this extra resonant peak at all times, even with the tone control on 10?
