This looks interesting and I will have to try it first, before I can say something. Thank You!
But it also looks a bit restrictive to me.
I was thinking about something like a drop-down menu on the Latest list where you can check/uncheck sub categories, or maybe something like that as a sidebar.
If you check or uncheck a category, the Latest list reloads with the new selection.
For example I would like to be able to get a quick overview over some chosen categories which I’m interested in right now, but maybe not tomorrow, but also be able to switch back to all latest topics, by pressing a default button or something like that.
Hope that makes more sense 