Thanks for mentioning that project. I'm wasn't familiar with it, but the difference seems to be that Jupytext is a tool to convert notebooks between ipynb and t

Thanks for mentioning that project. I'm wasn't familiar with it, but the difference seems to be that Jupytext is a tool to convert notebooks between ipynb and text formats, while VSCode supports the same format (#%% cell delimiters) but enables you to edit text-based notebooks similar to how you would in the browser, including keyboard shortcuts to execute individual cells, it'll render the markdown, and so on. I'm not sure if I understand your kernel question, but VSCode's Python extension has everything built-in. As soon as you add a #%% comment it considers what follows to be a notebook cell and automatically gives you a "run cell" button that uses your chosen Python interpreter.