This is quite an interesting evaluation, thanks for sharing. We are piloting with a large enterprise (100+ SREs). Before us, they started implementing Jupyter Notebooks in a similar direction.
Writing one playbook in Jupyter is easy but creating a framework to enable their 100+ product teams to self-serve and create playbooks has been so intensive for them, they even started working on their internal SDK for it.
It was a lot of code and the lead felt like the Jupyter visual interface was harder to follow for instructions/runbooks.
Thanks for sharing about Nurtch & Rubix, I have come across it before in the Gitlab Runbooks.
The Jupyter part is reference to the cellular execution of tasks as per the preference of the users + being able to get execution / code next to each other. Both have been design principles for us from the get-go.
Just like how variables can be reused across cells in Jupyter, we plan to shortly introduce rules / conditionals creating interdependencies between variables in the PlayBooks steps.