It’s pretty unusual for me to want an app to lose a feature, but this one is an exception. I would love for my downloaded books on iOS not to be synced anywhere - it’s so easy to download books individually and the syncing system causes me endless confusion/problems.
I like to download a book that I’ll be reading regularly, and remove the download once I’ve finished. I regularly find that the app either redownloads these books or fails to do so causing error messages, or pushing ahead of an item that I desperately want so that the item I most want is put to the back of the queue. On my mac it says almost 500 books are on my iPhone because it’s not syncing my choice to remove them properly. Realistically the number for me should be closer to 100.
Alternatively, if there was a way to see the download queue, the syncing error would matter a lot less to me and let you keep the advantages that it offers. Right now - for me at least - it causes more problems than it solves.