Public Chat Topics - Separate rooms?

Hello - brand new to OpenFire. I have a server up-and-running, and doing some testing. It looks very promising. However, a question arises - We’ll have about 600 users. A “Public Chat Room” is OK, but we need to have the ability to have separate topics.
It looks like I can finagle this by creating brand-new “public chat rooms” on-the-fly, with the topic as its title…I’d “retire” various “rooms” after the conversations petered-out, so I wouldn’t have tens-of-thousands of them.
Currently our users are on FaceBook in a private group. The number of active topics currently ranges to about 20-60 before aging-out. This seems doable to me, but I wanted some feedback by more knowledgeable people if this is the best approach.

Thanks!

Creating so many rooms manually by administrator is not the best option. Maybe you can just allow users to create rooms on their own?

That’s basically what I’d do - have a “New Topic” button which spawns another public chat room. Only the nomenclature would be different. This would all be done programmatically through the REST API.