Yes its possible and works, but as Sean said its a little bit tone sucker (like most pedals also from my point of view), if you only change/tune down 1-2 steps its somehow ok... but still not comparable to real tune change
what went into my mind, in case you are happy with the built in effects you can use your pedal in the pre-loop, which is midi switchable, so the Pitch would happen where it should be in case of downtuning - in front of everything else... from my perspective a tone improvement of having it post pre-amp