I am strongly calling for implementing shape control of the envelope in the ADSR modulator. This is a very expressive tool that I always find myself want to be able to control.
To be clear, I want to go from this:
to this:
(Screenshots from Analog (1) and Operator (2))
There are some different ways of doing it, Analog has an option of either LIN or EXP, whereas Operator has percentage control of the slopes (which can also be edited with the blue dots in the GUI). Depending on the complexity, a suggestion is that you could first go with the Analog way of implementing it and later go to the Operator way. The more options the better 