This is my concern with the proposal. I don't think that describes chat at all, the backlog is generally lost to time if people aren't there and joining in the conversation. And that's a benefit of chat. But we shouldn't expect that people read a chat room unless we've requested their attendance ahead of time (meeting).

Personally, I'm not super active in the chats, but when I do check in I haven't seen them overflowing with messages or situations where on-topic chat is blocked by board discussions. There's a rule on the internet about only making mailing lists when it has become painful, and rarely even then. The downside of segregating chat is that it makes the project seem less active (no one is chatting) and people don't see ancillary discussions (that they may not have realized applied to them).

Ted