But, it cannot convert OneNote headings in page to PDF bookmarks.
Gem for OneNote v42 add a new feature - Save Page as PDF.
It save current OneNote page as PDF file, and convert the headings in page to PDF books.
Gem's feature - "Save Page as PDF" is in "Gem" tab -> "Save As" menu.
OneNote Headings & PDF Bookmarks
Open this PDF file with Adobe Acrobat or reader, it will list all the bookmarks. Click the bookmark will jump to the related position of the heading.