Would be interesting. Here they used custom header links (not sure if that's an extension) to add a "Home" button. I think that's the best way to do it.
If the big logo lead back to another website, there would be need for another "forum home" button, which would be tricky to add with a plugin like the header links, as it would probably reset the one-page app ?
Either way that's always possible to create an extension to do the exact thing wanted.
