I understand that having a public chat can sound like a lot of fun. But, from past experience, they tend to get pretty hectic. I recall when we had one and someone would chime in with "dead chat" every time I took more than a few minutes to respond. And whenever the chat wasn't "dead", that question would get buried before I'd have a chance to reply. It wasn't exactly fun or productive.
I much prefer the structure and pace of a forum, where everyone has more time to craft their responses. It also allows users to easily find information without scrolling through endless chat messages. So, while I appreciate your suggestion, I'm really not on board with the idea of moving back to a public chat.