My guess is that it could be done. For instance I'm guessing it would be possible to have a circuit built that would set the low pass filter at 3kHz and the Q at 6db, and a second circuit for 2kHz and 3db, and then a switch position to choose the normal circuit. I'm guessing that because of the bench time involved, it would not be inexpensive. I'm also thinking that it might be impractical, because the sweet spot that you like today might change a few months from now, especially if you change amps or speaker cabs. And if you change guitar players, the tone that cuts through against a strat might not be the same tone that cuts through against an LP. And if this mod were for a new instrument order, you wouldn't know where the sweet spot was to begin with. To make it user variable, you would probably have to have an extra set of low pass filters and CVQs for each switch setting.