What about what it currently does for tabs? the tab for this thread says:
/sugg/ - Yo. I use the rec…
Could do something like that.
The recent posts section could be kept, just add a recently updated threads below it.
This is something that I'd like to be easily seen. I just open uboachan and close it almost immediately when I see my thread hasn't been updated in. /Recent/ is too cluttered for that and requires lots of scrolling to see what threads have been updated.