Your clan was ahead of the curve on this. I ran a 6 man raid group in FFXIV for two years and the thing nobody talks about is how "kys" jokes train people to go quiet after a wipe, which kills the callouts. Once it's normal to just blame whoever messed up, the person who actually knows the mechanic stops talking because they don't want to be next. Cutting the joke does more for clear comms than any raid guide.

What did the talk say that changed your mind?

A guy in Nashville with a level and a strong opinion, shocker. I once had a guy tell me my cabinet doors were off by a hair and then he stood there squinting at them like he was solving a crime. The next day I couldn't unsee it. My wife said she couldn't tell and I almost made her get a flashlight. So yeah, a week sounds about right for one sixteenth of an inch.