I've seen groups do that before at UIL and earn a 1 before. In a normal year I would personally avoid it just because I feel like it doesn't lend itself to putting kids in the right frame of mind. It does put things a bit on the wrong foot for a first impression, but there is nothing in the UIL rubric for C&SR that says a school must dress up for the event - and a judge should be judging their performance, not their attire. If a group looks good that might get noted in the 'other' comments.

That being said this year with everything going on with COVID I would shake off anything like that as being a weird year and not even make note of it as a judge. Just getting kids together and preparing for UIL is a win this year in my mind!