Personally, I prefer a different approach to mono/stereo wiring.
Instead of having seperate mono and stereo outs, I would rather have two mono outputs with break terminals that disconnect when a cable is inserted. If you wire the tip terminal on the first jack into the break on the second, and the tip terminal on the second jack into the break on the first, you can have it so that when you plug a cable into only one jack, (Either jack, it does not matter.) you have a mono output, but when cables are plugged into both jacks, you have a stereo output.
I guess it's personal preference though, depending on if you like both signals in one cable for stereo, or two separate cables.