If you're unable to send multiple Syphon outputs, then you may be able to achieve this using just one output: You could have 2 different effects for MixEmergency (e.g. SendRecvLeft, and SendRecvRight). Both send the input of the MixEmergency effect to Resolume, which then takes the footage, effects it, and then composites it on an output that is twice the width of the frame. One side would be composited on the left side, the other on the right. This would then be sent back to the MixEmergency effect via Syphon, but the left effect would only display the left half, and the right would only display the right half.
