Recently I discovered that reading my book in Kindle Direct Publishing's ebook previewer taught me some lessons I hadn't learned by reading and re-reading my book in a word processor and on paper. Specifically I learned to use paragraph breaks in a new way for e-publishing.
Preparing my book for publication as a paperback has yielded still more lessons. Perhaps because throughout my life I've done most of my reading on single-spaced, facing pages, I never had to think of how the eye and the mind work together to turn those ink-blots into images and thoughts.
I've been over Dark Mural so many times in the past two years, I have parts of it memorized. Yet, when I saw it in the familiar form of a printed book, it looked different and read different. I became aware how parts of a scene fit together and raised questions that would be answered on the following page. In a few instances, I saw how the scene could be better built, and I've made changes.
Of course, most writers say they always want to change things, even after a book is published. So perhaps this was just one more opportunity for me to see such things. But I really don't think I would have seen them without reading it in book form.