It might be useful sometimes to have an option to switch an instrument-envelope on & off with patterncommand (like for volume, panning etc.)
this could look like this?:
Ex0x (e.g. E101 or E100 could be volume envelope on and off etc.)
This could be a way to avoid doubled samples like if you have a substain in an envelope which you don´t need at a specific time and you´re forced to copy.