I didnt bother reading all of the above, so I take it you have your answer by now!
just wanted to say that I did a couple different things on my Korg M50.
I didnt have a sustain pedal but I had a pad and a lead sound mixed into one combi. So I assigned the Pad+Impact to an arpeggio AMS that did not fluctuate ( an "arp pattern" that did not arpeggiate) and then set the arp pattern to "hold" so that when I hit the key.. it would just sustain..like a sustain pedal XD! Then when I did acquire a sustain pedal, I added it into that equation and after correcting and assigning the channels, I simply had the sustain pedal for the lead on the right hand and the pad+impact with the "Hold" option in the Arp settings sustain that pad ( with an added heart beat if I can remember.. that was arp pattern B too! )
I think editing the Release and sustain inside the filter settings on some sounds ( or maybe all sounds..?) will carry the sound over as you progress in playing. and by assigning sustain and release to knobs if you have them, makes that much more flexible and fun ( of course) !
I'm new to the forums and Im not much of a keyboardist or a pianist.. more of a drummer. But I thought I could try my hand at the whole "posting" thing.
-Z