It would be nice to have to have tittles with hundreds of chapters nested into its published volumes. I believe by implementing this would make browsing for chapters easier instead of scrolling down to the bottom of the page and having to click the next page button in order to find an earlier...
Being able to toggle multiple chapter read statuses (the eye icon/button) after, for example, reading hundreds of chapters of a series that you follow/bookmark after.
Or at least have the 'Reading Progress' form actually toggle those icons.