This extra envelope stage is so incredibly useful for sound design it's surprising that it isn't a standard feature on all modern synths. And unlike various other multi-stage envelope schemes, the addition of a fall/rise segment doesn't overly complicate the programming experience for new users.
So I am respectfully requesting that a new "Modern Envelope" or "Multi-Envelope" be added to Diva's feature set. It would be easy enough to add this additional parameter to the envelope without completely redesigning the UI. For instance, I think you could probably remove the KYBD (Keyboard) parameter from the current envelopes and replace this with the Fall/Rise parameter (and then move the Fall/Rise segment after the Sustain stage). That would be an acceptable trade-off for many people.
Incidentally, I am NOT requesting a more advanced multi-segment envelope that has an arbitrary number of stages/steps (with different curves per step) that can be synced to MIDI clock etc. While that would certainly be cool, it would probably be a much more involved addition and might be better included in a "Diva 2.0" update down the road.
The modulation in Diva sound stunning - I mean, there may be a reason why they did not add it, but that also being said, if it would sound still so great and F/R (or even MSEG) would be added, that would be coool. 
