The Inaugural Star Wars Half in 2015 also featured people dressed in full jawa costumes and somebody, inexplicably, as Jabba thet Hutt. You couldn't see any part of them underneath those costumes. There's a reason why runDisney changed the costume rules after that race weekend.
I also saw people dressed as Mrs. Potts and Chip during the 2011 Disneyland Half. Usually pulled off to the side of the road trying to deal with the heat and those costume choices.
I understand why people want to run in costume. It's certainly fun, but please make sure that if your goal is to finish the race healthy and upright that you choose a costume that will safely allow you to do so.