I'd probably vote no for a child board simply because I feel LAF is already far too subdivided. I can count on one hand the number of times I even think to visit the child boards when viewing here.
I haven't looked, but I know most forums don't have "tags", which would be a much easier way to search threads, etc. If you could simply have [Star Wars] and [28mm] added to your post, and people could search by tags it'd be a bit easier. I haven't even looked for that feature on this forum though.