When we create ebooks we usually we do the design in Canva, so several people can see the file and give feedback directly on content and design.
About white papers/research papers for collecting data we used Survey Sparrow (
https://surveysparrow.com/)
Also If you have a lot of video interviews to review I recommend DoveTale App (
https://dovetailapp.com/)
Creating content like ebooks/white papers is great, but if you fail to create a ebook/paper that brings value it can fire back very bad.