I usually have the output from my OP-1 go to a Reverb pedal. Sometimes I don’t want the drum track to also hit the reverb because it gets too muddy.
I recently found a useful trick to have the drum track bypass a pedal. I can use the OP-1 mixer to pan my drum track all the right and the other tracks all the way left. Then I use a audio splitter out of the OP-1 and have the right (drums) bypass the pedal and the left (everything else) go through the pedal. Then I have a cheap mixer that mixes the stereo output of my Reverb pedal with the drum track and voila.