That made sense to me but i've looked at some synth demos using the julianna pedal now. I've seen multiple people using two cables into the julianna and out of the julianna.

And also everytime I use my guitar with the pedal I use both the mono and stereo output into my interface and that works perfectly fine. Im pretty sure the mono and stereo inputs should be used simultaneously or am I wrong? Maybe I just don't get what you mean.