While I'm in a "cleaning up" frame of mind I decided to get rid of the Ultimate Category Excluder plugin I was using to split old posts into an archive.

Instead, I now separate them using a simple if statement at the same time that I exclude microblog posts from the main feed:

if( !is_archive() ) {
  set_query_var('category__not_in', array(81));
  // Exclude from all but archive pages

Having a plugin installed just to achieve that is wasteful and an overhead I can do without, but it also makes me realise how much has changed since I first added the microblog.