I agree about the splitting of monitor outputs. Likewise, equipment rack LCD monitors are relatively common. With the crossconversion to component and video on the second zone, however, I doubt the designers expected users to have both the s-video and composite monitor outputs used up for things other than an LCD monitor of this type. Your scenario proves that it can happen, but before you presented your scenario I would not have predicted a case where the composite or s-video monitor out would not be available for an equipment rack LCD monitor.

Since we don't have the OSD on the second zone, maybe we can brainstorm a bit. Can you give a detailed summary of your system? Based on this post (which indicates both of the TV's connected to the monitor outputs are part of 7.1 systems), it seems clear that we're dealing with an unusually complex system here - three active video displays, each with (presumably) separate surround speaker setups, plus an LCD monitor at the equipment rack as the fourth display in the system. It might be helpful to know the full details of the audio and video signal paths involved. Maybe we can find a solution that is better than splitting a monitor output...