OK. Sorry for not being clear enough. I'm outputting stereo audio; nothing too complicated. I have a multi-channel soundcard (actually 10 channels in/out). Within OSX (in the Audio Setup utility), you can configure a set of channels to be your default "speakers". The web browsers, iTunes, and others use these set of outputs as the default for sending audio. In my case, I use channels 7 & 8 because of how my mixer is setup. Applications that are truly multi-channel (things like Garage Band, Logic, Amplitube, Reason), let me pick channels specifically for output. It would be very useful, to me, for Cog to be able to either a) use the set of channels set as "speakers" in OSX or to be able to pick channels specifically for output. Cog appears to send audio to the first two channels no matter what I do (I can tell because it comes through my control room rig on 1&2 rather than my monitors on 7&8 like all the other audio apps do).
I know this is probably obscure, but I like cog for playing back my FLAC's (I'm a recent Windows-switcher) while I'm working on the studio rig.