An idea for forum 'filtering'

There's been over time discussion on the content seems when you come to Stardock's forums.

JoeUser, Wincustomize, GalCiv etc.

Stardock have made a fantastic effort at letting all these forums interact as one giant community. But for some people it's just too much.
e.g. I myself only use Wincustomize as my gateway - but of course I see other kinds of post from the other forums too, because they might share a forum.

But if we separate the forums, you separate the communities, and being able to cross-post/expose isn't necessarily a bad thing, especially if you are active in multiple communities.

So it seems impossible to resolve this.

My idea: What about allowing a user of each forum the option to filter for threads *started* from a particular forum.
This means users from sister forums can still reply and participate in topics, but they are presented only with the posts created for their selected filters. If a GalCiv forum poster wanted to start a topic aimed at all skinning type people, they could select it as a 'Wincustomize' post and it will then show up clearly for users who have 'Wincustomize' as their desired filter.

If the poster don't specify the sister forum - then they miss out on those people filtering out GalCiv created topics, but still are seen by users from sister-sites who indicate they are happy to not filter out GalCiv created topics. (I'm just using GalCiv as an example here)

It might be just enough to allow a balance between cross-community sharing and also being able to focus on just your primary interest community.

Could be a silly idea, just putting it out there