I'm not sure if that would be the case. I am one that often spends time in chat to talk to everybody. In the cases where 15-20 people are on the server and you need to speak to a small group of 3-5, such as building and group mining, a separate chat would be ideal. Another option is having a separate chat assigned by a moderator or admin to a specific person and that person allowing certain people in the same way as IRGs. Then, when the project is over, the chat is removed. (This may mean Niro has a permanent one due to the amount of projects he runs...)