I would imagine it would be possible if you were just blending the middle pickup with one of the outer pickups as you operate the blend. But having a system where you could say, have the neck pickup only on full and as you move the blend knob towards the bridge, the neck pickup level fades down gradually and both the middle and bridge enter the signal in some kind of proportion relative to the knob position so in effect all three are on all the time but in various proportions over the sweep. And switching system to switch in each type. My mind boggles with the kind of options you could have if it could be done.