We started doing these, and after a few months, I started advocating that only ONE engineer needs to be in there, instead of all 12 of us. If that engineer has

We started doing these, and after a few months, I started advocating that only ONE engineer needs to be in there, instead of all 12 of us. If that engineer has a question that only someone else can answer, they can just pull us in (has happened ZERO times). So, now we just send a sacrificial engineer to do refinement, usually picked by whomever did the fewest code reviews since the last refinement. It's actually worked too well. I get code reviews in 10 minutes instead of hours.