Would it work to say that you don't change the reading state on auto-updates? So if I have a purchased and side-loaded KePub with some percentage read, when I reset and reload these would be unread (except the purchased one may already have it's reading state set). Then the plugin would not update the side-loaded book because the reading state is different. Similarly, the purchased book would either be a different reading state or identical and not updated anyway.
Or I'm way out in left field
