Here's some interesting data from the site listed in the OP,
Pen America. https://pen.org/report/book-bans-pressure-to-censor/
37 percent include themes or instances of violence and physical abuse (n = 2180). Of note, within this category, 1,134 instances are books that include episodes of sexual assault, which is 19 percent of all instances of books banned.
27 percent detail sexual experiences between characters (n = 1,560).
They don't give any figures for overlap, if any, in their statistics. But the above represents about half of all books banned by public schools.
That is about half the books banned include explicit sexuality, domestic violence, or rape sequences. I really don't see how material including any of that is subject matter for a K - 12 public school in any form. That's for starters.