This one fell prey to a common problem I have with a lot of isekai: the beginning premise is interesting and the first few chapters were fun, but at some point I just got bored of the writing. 20 chapters doesn't feel like a lot, but by ch 20 I felt bored and wasn't really interested in the new characters.
The Villainess, Cecilia Silvie, Doesn't Want to Die, So She Decided to Cross-dress!