Haha I had exactly the same question as I typed my response and checked if anything like that is done in the example project. The best I can come up with is that the version of Jupyter server is different in the new images so it’s possible the defaults to where the config files are picked up from have changed. I think this also led to the streamlit template “breaking” a few months ago.
In any case, I’m glad this works now - I wonder if it would be useful to include some generic instructions about such a use-case in our docs? I would be very happy to review a PR that added it! 