"There is an option to get early access to new releases of Microsoft Office MacOS Apps by selecting [Join Office Insider Program] in the Microsoft Update App. Similarly with OneNote there is an option under settings / preferences to [Access Experimental Features] both in iOS and MacOS.OneNote update preview – Paul Carpenter's Tech Blog
The preview OneNote app sports a redesigned interface with sections appearing hierarchically between Notebooks and Pages in the left hand pane. The new arrangement is not only aesthetically pleasing but also a more logical way to navigate OneNote content."
Thursday, October 13, 2016
OneNote update preview – Paul Carpenter's Tech Blog
Worth exploring, if you're a macOS or iOS OneNote user