Generally I’ve found people are well behaved, and CMs will stop people running. Not a Black Friday situation at all. There will always be a handful of people that will weave their way through, try to run up the sides, etc, but it’s pretty tame.
Overall I think the most unpleasant part is that you’re doing a relatively slow walk in a large crowd. I know I have to make an effort to slow down my regular “Disney walk” lol. The walk back to MFSR feels like it takes forever in that crowd, although it definitely depends where they’re holding the crowd.