Some suggestions to improve this feature:

1. If I embed a file that is already in OneDrive or Sharepoint, OneNote should detect that and embed the original file instead of creating a new copy and uploading it somewhere else inside OneDrive

2. OneNote should allow you to edit embedded Word/Excel files directly from the preview (at least do basic edits)

3. OneNote should index the text from embedded Word documents, so when you do a global search, you can find text located in those files as well

Hope that helps!
Ángel.-