[virtual-signal=signal-1] E.g. Take the 1-5 from "Sub-tree merge". [virtual-signal=signal-2] Looking at the outputs, the three output splitters not only output the five outputs, but they also output one loopback. Because the loopback comes from an output splitter, it is also balanced with the five outputs. [virtual-signal=signal-3] This means that any of the five outputs can serve as the loopback instead, [virtual-signal=signal-4] possibly leading to a more convenient layout.