You'd need some really great moderators for this kind of conversation. No conversation is perfectly linear - new ideas lead to forks, and a large group needs to

You'd need some really great moderators for this kind of conversation. No conversation is perfectly linear - new ideas lead to forks, and a large group needs to somehow choose whether or not to take one. But if there's a queue of five folks waiting to speak, that's four opportunities for the tangent to either be taken or not taken, and exponentially many opportunities for the wrong tangent to be replied to.