I do like when books are unique, such as visually showing a letter or something like that, but if I can’t quickly and easily read a page, I’m completely turned off. For example, I wouldn’t enjoy what you described in your friend’s book because it would probably slow me down or take away from my immersion in the story.

I really appreciate artistic freedom, but I do think the reader’s experience needs to be kept in mind if you want to publish a successful book.