The problem with splitting Project Announcements into build-type sub-forums is that you get less eyes seeing and helping with projects.
Unless you browse by "Unread topics" like some of us do...
That gives you every unread posts from every sub-forum.
Keeping up with all that isn't worth the effort IMHO -- nine sub-forums is more than enough for me.
So we are expecting people to properly tag their post? The same people that can't find the right sub forum and can't put their location in the title of their BST threads?
Riiiiiight.
Tags are optional. If someone isn't willing to make the effort, that's their problem.
Also if they post in the wrong subforum and the mods don't notice/move it, tags can make it easier to find.
That brings up the question of whether only OP can tag the thread, whether other posters can tag it, and whether the tags can be edited after postng.
One other advantage to tagging is that it can make finding examples easier on seemingly unrelated sub-forums.
(i.e. finding posts about pincabs in Woodworking)
Scott