My latest obsession has been using one of the bus outputs as a FX send to some guitar pedals then back in via one of the inputs.
Currently i’ve got a fuzz, phaser, flanger, and compressor in the chain to really spice up the internal synths and anything else I plug into the other input.
If you haven’t already checked out this discussion Monomachine Love Thread I recommend you do. Tons of cool ideas to get you going!