@kiwidude - Thanks for all the great plugins! I use just about all of them regularly, and truly appreciate all the effort you put into them.
I have a suggestion for another quality check option that I (and hopefully others) would find useful. I always do an ePub to ePub conversion on my books, primarily to adjust the fonts and to insert the metadata page (i.e. book jacket). I would be useful to be able to check for the existence of the metadata page to determine whether I have missed converting any books.