To your point of non-abelisaurids not being described, I was invited to visit the repository in India that houses the
Dravidosaurus specimens.
I remember seeing about a dozen cardboard boxes labeled with their localities.
I looked through some of them since they were all undescribed but soon realised that most of them are either abelisauroids or just lack any identifiable features.
However there was a box full of random ?dinosaurian centra and a couple of them didn't look abelisaurid, although I have no pictures of those bones (They lacked pleurocoels, and were above 10 cms in diameter).