NotebookLM launches feature to customize and guide audio overviews

Not an improvement for me. I've been instructing NotebookLM for weeks now already by including the instructions into the sources. That way I have version control on my prompts and can easily drag into the sources upload. This requires finding my instructions and copying and pasting, there's also a 500 character limit which is very small, I have over 2000 characters for my standard prompts.

I think it's an easy affordance for those users who are just interested in the basic functionality of the product.

However like you I cottoned on early that one could put a "Podcast Production Notes.txt" in each one of my Notebooks that allowed me to really put some horsepower behind the generated audio :D