Local vs Cloud Storage
Having OneDrive integrated with OneNote is definitely a plus, but it would be nice to also have it saved locally for when an Internet connection is unavailable.
We just announced this week that OneNote Desktop (2016) is going to stay supported, as well as put back into the Office 365 ProPlus and 2019 installations. We will also be making future improvements to Desktop. This will give you the option to keep your notebooks local as long as needed.
Details in this new blog: https://techcommunity.microsoft.com/t5/Office-365-Blog/Your-OneNote/ba-p/954922
Please add the ability to backup at a set interval in the Windows Store app the way you can in the Desktop application.
For those of us that almost exclusively use the App, it is really frustrating to have to open the Desktop application to actually have my Notebooks get backed up.