When checking kagi.com/news the first thing I do is to open the "Australia" category, since that's where I live.
This category choice should be sticky, and remembered for the next time I visit kagi.com/news
A user wouldn't notice this proposed feature, and it wouldn't require any preferences or UX.
The last category visited would be remembered (in a cookie or in my user profile), and visiting kagi.com/news would show me the last category I examined.
I notice you store last_map_position in your current cookie; so this would be similar.
