hexagon

You may be right about the Kontakt format being proprietary— I am not sure about that.

What I mean is, in Keyscape or Omnisphere, when you release a key, it can trigger another sound. It is often used to mimic the natural vibration and finger sounds that actual pianos make when lift your fingers off the keys. It may sound like a small detail, but when you hear it in action, it really is amazing.

You can hear it in some of these examples: (jump to 4:24)

I do not believe it is just jumping to the loop end of the sample you are playing.

I suppose this is more of a nice to have than the bullets above it, which really would make a big difference in making Deluge's sampler more organic sounding.