I absolutely love that Joplin now allows sub-notebooks. However, when I am looking at the list of notes I have in a notebook, I would also like to see any sub-notebooks. I made an example of what this could look like,
I also do not see the benefit of showing sub-notebooks in the notes panel.
Compare it to an email client where folders and sub folders are shown in the west panel, it would only be confusing to see sub folders in the mid email panel.
I guess I was think more about how the filesystem on a computer works, where you see files along with folders. However, I understand the issues listed here.