It definitely has a place for filtering purposes and also for content exposure.

I think it'd need refining in a way that territories have yet to have been refined. There's a lot of bloat on SN after the introduction of territories. Some that have next to no interaction nor an active founder. Just dead territories that are likely to be archived. I'd like to see that play out before adding more smaller territories to the long list of areas to post. Otherwise the checkbox list gets really bloaty really fast.

Unless you organise the checkboxes as a drop down? Once box checked also show options within territory? Dunno, would have to think about how that would work. I'm not a coder so I wouldn't know how that would work.