I wanted to request this feature because getting the envelope of a synth would be incredibly useful for music creation tools on Playdate. It would make it a lot easier to both display the current envelope and update it by increments. I think it would also be helpful to have accessor functions for each segment of the envelope (getAttack(), getDelay(), etc.)

What about setting those properties?

There are already functions for this, setADSR(), setAttack(), and so on here.

Try the tool I made. It allows you to test the envelope and change it on device.
Check out the source code too, so you can maybe implement your own get functions?

Thanks for sharing this, I'll check it out! (I still think there should be official envelope accessor functions though :P)