within a vol pedal, theres usually only 1 single pot wired as volume control. Its an extremely simple wiring.
for the low and high impedance, only difference is in the value of the pots.
to have one volume pedal to cater to both, its possible, but not sure if theres any available readily. If handy with diying, can try a dual ganged pot in place of the usual single pot.
That said, finding the correct value dual ganged pot and a volume pedal that can housed it without changing the layout of the structure that holds the pot aint so easy.
theres an easier method to have both though, 2 vol pedal, 1 hi impedance and 1 low, plus an a/b switcher, it will do the same thing.