This part of the manual is taking about routing modes. If you set the PitchFactor’s routing mode to Wet/Dry, this means ONLY one side will get a mono version of the effect, but not both. You get to decide which side with Wet 1 (Out1 wet) and Wet 2 (Out 2 wet). The other side is always dry. If you set a preset to Stereo, the pedal operates like normal, not mono.