Hi Stuart,
Looking at the configuration management log it appears that since the dawn of time (13th June 2003) that topics and weeks have been separate from a formats point of view. The person to answer this will be the man himself, Martin.
For the most part the code is the same only with subtle differences dotted around the place. A while back I merged the Collapsed Weeks functionality into Collapsed Topics as noticed this very same thing. This saves a shed load of maintenance for the sake of a little switching based on a setting.
Cheers,
Gareth
If you wanted to go further could replace those collapsed formats with some simple css ?
http://jsbin.com/ihOleqa/2/edit?html,css,output
(currently you'd still have to add some minimal js .focus() and aria expanded etc for screen readers)
Yes and no!
Nice use of target pseudo selector. But CT already does the display none / block switching in CSS for the core functionality. Its all the other bits like AJAX toggle state, columns and colours.... that take up the bulk of the coding.
G