Completely against. Half of their purpose is to control kids and try to force this weird discipline of "all of you look the same, there are no individuals". Yeah yeah, some people can argue "but uniforms prevent distracting clothes!" Okay, that's an easy to fix problem, have rules against those clothes, and offer substitute clothes if the child comes to school wearing i. Problem solved! It's such a bullshit, cop out excuse.
The other half of uniforms purpose is to sexualize young girls and "teach" them about how a woman "should" dress. Hence why almost every single school uniform consists of a skirt. Doesn't matter how long or short it is, girls are in a skirt. Why? To feminize them. "You are a girl, you wear a skirt!"
Honestly, I'm surprised these religious/private schools don't have a class dedicated to indoctrinating young girls with the "you will be a housewife who bears children" mentality.