My mother and sister as well as some of my sisters friends were involved with them, I find it to be a very disturbing bizarre subculture, where girls are taught looks are everything and how to be backstabbing and evil while putting on a fake smile, it's very superficial a bad message to send to young girls. Mostly I was dragged along while my sister preformed, I think it left her with rather weird values or maybe just that is how most people see things , but most of those girls become the worst kind of people , many were the ones who bullied me in school.
I also would have concerns of how sexualized the costumes have gotten, very disturbing to see young children dressing up that way, it wasn't quite like that in my youth all the clothes were seas of ruffles and ribbons and the skirts still often long. They are private now to only family and the judges so not so likely to have weirdos in the audience , but still unless you are good at social politics and back stabbing it's best to avoid.