I use notebooks the whole time, normally in vs-code and with github copilot setup. I found it quite painful to point it to a couple of environments I have, and confusing how i get it pointing to my gpt4 api keys. Once I did these two I was not sure how to prompt rather than typing a command. Good luck with this, don't mean this in a critical way, just trying to give some feedback of what I think when I first try it.
At the moment you press `g` (for generate) while in command-mode to create a "prompt cell". I'll think of ways to make this more obvious.
Appreciate you spending the time to try it out and share your feedback.