Hello. I tried the Scrivener 3 trial and loved it. But I noticed that, when exporting my novel to any format (PDF, EPUB, etc,) the page layout wasn’t the same as how I laid it out myself. For example: my novel doesn’t have sentences that continue on to the next page to allow flow to be maintained, and there’s illustrations. The main issue is that, when I render to PDF or EPUB (or any format), a sentence will, in fact, extend to the next page rather than end before the page ends. Additionally, fitting the image to the entire page will cause the image to extend to the next page when rendered. I know what you’re thinking, “user error” (and I thought so too,) until I tried everything, looked up tutorials and had a friend of mine, who’s a Scrivener 3 user, help me in a Discord call. Needless to say the issue persisted. Maybe it’s a bug? If so, before I buy Scrivener 3, could anyone confirm this to be true or not? Thank you.
The problems you are observing are among the countless many reasons for why we call Scrivener a writing program, and not a book production or publication platform. I appreciate that you are doing what you are doing to make the book look good (and wish more people thought of those things!). The importance of that job though is why I wouldn’t want someone to use Scrivener, because its near complete lack of page layout code makes it uniquely bad for that phase of proofing.
Thanks for giving Scrivener a try, and I hope it suits you for what it is meant to be, but if you were looking into it as a replacement for special purpose software like InDesign or something… well that’s an area we aren’t interested in. Snapshots, revision tracking, a corkboard or outliner, and so forth would have no place in such a tool, in my opinion.
As for ePub though, Scrivener’s good for that, and the reason for that is that you’ll need to adjust your expectations for it. There is no proofing for ePub like you’re trying to do. Think of this way, one person’s book reader is going to be the physical size of a business card, and another person’s may be the size of a film poster, and either one of them can change their ebook reader’s font size to be anywhere between gigantic or tiny. There is no page layout level proofing that is conceivably possible within those parameters. You don’t even have control over the fonts being used, the line height in most cases, or the margins. So within this greatly simplified approach, a program like Scrivener that just needs to get the code of a book right, can do the job well.
Print though, that’s years, maybe even over a decade, away from where we are in terms of programming, and in a completely different direction than where we went.
So again, I hope you do find a use for Scrivener, but maybe it will be for the next project, where you’re starting with a blank page. That’s its sweet spot. 
I see. Thanks for the reply. I’ll stick to LebreOffice Writer, then. Take care.