In the midi control change section of midi implementation it mentions a cc value for sustain and a couple of other parameters has anyone tried these? Also what do people think the possibilitys are of modding a sustain control on to the front panel are?

I think the “Sustain” mention in fornt of the MIDI CC#64 is that sustain triggered by a sustain pedal. This is the usual number ofr that control, IIRC.Plus if it was any envelope sustain segment, I think you would have read “Amp Env Sustain” or “Filter Env Sutain”.