I've been working on this for days with limited luck. As a heavy user of Onenote, I'd really like to find the most accurate way to this so I don't have to reinvent the wheel in Evernote.
Here's what I've tried:
Evernote Legacy app import: This works, but tags are everywhere and does not resemble the Page / Sub page that I've created in Onenote. https://sspeiser.github.io/onenote-export/ In my first test, I can't get anything to work. My Onenote is big, so this utility stops working at 265MB, then hangs. https://janikvonrotz.ch/2020/07/01/01-bulk-export-onenote-notebooks-to-markdown-