Yes, you can use the supplied leads for that, or anything that ends in a 3.5mm mono jack on the MB side. The EXIT IN jack socket is mono, so stereo will have no effect - in fact, avoid stereo, as one of the channels bay get shorted out in the moo socket.
Note that the signal levels in the patch uses high signal high levels, like those used for modulars. So to take an an external signal from something other than modulars synths (guitar, microphone, mixer, other synth etc.), you may have to use a preamplifier that raises the signal to modular levels. Just try your extrenal signals first - if they're too low, then look into a preamp solution.
