Please elaborate what grouping and the duplicate check should actually do. I'm not quite sure yet what the actual feature request is.

My immediate problem (but I've had other situations) is that I have one instrument for solo violin (arco) & another for pizzicato. I will also have another instrument for the harmonic string. Under normal circumstances, they can't be played together. But I need these 3 separate instruments to cut each other off when one of them plays. Since I track one string to a track (G4, D5, A5, and E6), I can at least control what each string is doing at any given time. But when I go from playing pizzicato to arco on a string, any sound from a pizzicato or a harmonic should be cut off when I play a note arco. The only way to get this done (other than the workaround I mentioned) is to group Instruments together, and then a duplicate check for "Instrument Groups."

Although, now that I think about it, wouldn't the NNA do this very thing? If I put my different instruments in one channel, the NNA would go into effect for that channel! DUH!!

Sorry, close it out!

Yeah, I think what you want here is NNA = Note Cut and DNA = Instrument + Note Cut or Note Off, depending on how you want it.