I just added parameter groups and envelope marking to 2 synth engines:
Calf Monosynth => It has a “sloped sustain” phase, so it’s good for testing the envelope widget
Vex => It naturally fits quite nicely the 4 parameters/page zynthian design, so i decided to make it was worth the effort. On the way i got hugely pleased by some VEX “hidden” features that i was not aware. I prefer to describe the details in this thread: