It was one of the selling points for me and I'm not seeing how this can be accomplished.
I have the "Board title" set to "This Forum" in Setup > Options > Basic board information.
For the addon, I put "This Forum - Site.Com" as the "Forum Meta Title". However, the title changes to "This Forum - Site.Com | This Forum".
I'd like the header to be "This Forum" and the title be "This Forum - Site.Com" as it appears in the screenshot.
Maybe a 2.1 Beta 5 issue?