Thanks for the post (and for all your work on Book Bingo) @misericordiae@literature.cafe !
I have completed about 9 squares (4 hard mode!), and 10th will be done soon. That's my next planned book. No bingo yet though, but there's still plenty of time. Have also done one alternate tile, so can just swap it with some uncompleted one if I get stuck.
One question: For 1E: It takes two, can other author be illustrator? Or they have to be the "author"?