Have not repatched for any parallel/series combinations yet, don't have a loop patcher at this time – a 1/4" patchbay to route all 8 ins and outs would be very handy in a less portable rack rig. The possibilities are indeed nearly limitless, I typically use three units for something like Chorus>Delay>Reverb and use the fourth for looper or special expression pedal controlled effects from simple wah to your wild meltdowns.