I think this project is great and I fully support it. However, it's only a list of books challenged by mostly christian conservatives dealing with race and gender. Left-leaning progressives challenge books ALL the time. This is bristling to hear, but it's true. Books that are deemed to contain racist or sexist words or images are challenged every year. Huckleberry Finn, Dr. Seuss books, books about Christopher Columbus. Go find the video of zealous high school students throwing out books they don't like in an attempt to "decolonize" the shelves. Go read about how librarians intentionally weed books they find offensive. [1] Sorry, but that is a book challenge whether you like it or not. Different people are offended by different things and they don't want you to see the books that piss them off.
I don't like any book banning or book challenges, we also need to keep the problem in perspective. There are 100,000+ libraries and ~170 million library card holders in this country. The vast majority of these challenged are from coordinated groups like Moms For Liberty who just hand over huge lists all at once. Each of those get counted as a "challenge". I sharply disagree with Moms For Liberty but this threat seems largely exaggerated.
[1] https://bookriot.com/weeding-racist-books-at-libraries/