In open circles, if the dancing gets too rapid or wild, participants can step back. Just bring your neighbors' hands together and move out of the way. Effective ritual evokes response. Novices are at different tolerance and skill levels than experienced ritualists, and some rituals can be overwhelming. Also, the 'boogie till you puke' crowd exhausts the older folks and the kids in the group.
Some rhythm is traded off for comfort.
It's a point. In that case, I think a clear understanding of what's to come would be essential. No. 4, Althea Whitebirch argued for informed choice in using stimulants. If alcohol is used in a communal cup everyone should know, and a fruit juice or other substitute should also be available. At least, not with my knowledge or approval.