I did castrum yesterday and didn't see one area where CS' s popped up during a fight. Only when people ran ahead and didn't wait for those in CS' s.
That said. I think watching CS' s should be mandatory and unskippable for first timers while those who have been through it should have an option to turn them off.
This solves two problems.
First timers not being able to watch them because of jerks running ahead and screaming "wach @ enn n00b" while also giving actual speed run groups the ability to do just that. Speed run.