The way I'm using the favorite system of chat.SE is that every one of the rooms I have in my favorite list is a room I want to be online in when I'm logged into chat. It's six rooms where I want to see if anything is happening, and when I'm logged into chat at all, I want to be logged into all of these rooms.
Now, there is a convenient button to rejoin my favorite rooms when I'm logged into only one chat room. The problem with that solution is that it doesn't appear when I'm logged into more than one room. This is a pretty common situation, I often have two chats open in different tabs. And when I suspend the computer and start it later, I'll get logged into those two rooms automatically, but I won't get the option to rejoin all my favorite rooms.
I'm not sure how other users use the favorite system, so my request to always log me into all of my favorite rooms might not be useful for everyone. But I'd like to have a way to keep me logged into all of those rooms, maybe some option in my chat profile. Another idea would be to always display the button to log into all favorite rooms, even if I'm in more than one room. But that option also might annoy some users that use chat in a different way than I do.