FYI, there's a great thread going over at the Harmony Central boards:
http://acapella.harmony-central.com/showthread.php?2460185-List-of-Synthesizers-featuring-rare-features...-keep-me-updatedIt's about special/rare keyboard features like poly-aftertouch, release velocity, ribbon controllers, etc.
I just put in a couple of comments there, including about the (as far as I know) unique Sustain I/II modes. Does anyone know of any other keyboards, besides the CS50/60/80 that have this ability to have a long release time but have new notes cut off old ones? I think it's an amazing feature of the CS80 and have never seen it anywhere else.
As I wrote, I think it would have to be done at the sound engine side of things. I don't know if it would be possible on a MIDI controller. I don't think there's any MIDI message to cut off sustaining notes. I don't even think a MIDI panic would do that.
David