Ed, could I please express the view that there are far too many sub topics?
This makes it tedious, particularly on the mobile site, when you are perusing the threads.
For example does 'Motoring' really need sub topics of 'Cars' 'Other Vehicles' and 'Road Rules'. There are usually none to view in the last two.
You could ditch all three and just leave one main topic.
Similarly 'Chatterbank' has 'Seasonal' 'Christmas' and 'Weather'.
Would anyone object if all three sub topics disappeared?
Those of us who regularly use the mobile site would be very happy, I suggest, if you were to viciously prune the sub topics down to a bare minimum.