It's always possible to add a forum--the real question is, "Is there any reason to do so?" We've considered proposals similar to yours from time to time but we've come to believe that we gain more by being together than separating ourselves any further than we already are. As things stand, we have separate forums for the Southern Hemisphere, for Canadians, Dutch, French, Portuguese, Scandinavians, etc...and in general these forums get very, very few posts. We've found that the more we subdivide our interests, the less interest there is.
That said, if there is a real need or widespread desire for something like what you suggest, we'd be happy to consider it again. If you want to pursue it, start a poll somewhere (Hearthfire if you want to open it to anyone or OBOD General if you're limiting it to members) and see what people have to say. If there are enough good arguments in favor, we'll revisit the question.