This is a great post. I've been advocating this for over a decade.

> The most important conversations are not always the ones that appear on the agenda. They are the ones that happen before the formal session begins, in the ten minutes after it ends, in the corridor while people are putting on their coats. These are not peripheral to the group’s work. They are often where the group’s actual thinking takes place.

This is a core belief. One, in fact, that at my last workplace, we understood well and designed for. After client meetings, we would walk clients slowly back though the kitchen and pause for a while there, splitting up into informal chats, before seeing them out of the door. Afterwards, we would quickly compare notes on all the things they said on the way out. These things were often the most important steers for the project.