I finished this project a while ago but forgot to share it on the list.

[sketch] is a tool for drawing polygons and Bezier curves into arrays, very useful for creating envelopes and custom waveforms. It's easy to use and state-saves automatically. Take a look at the attached gif to see.

You can find [sketch] in the Context library:

https://github.com/LGoodacre/context-sequencer

It requires several externals.

I hope someone finds it useful!