I just wanted to say a big thanks to @creedon for this. It has lifted my Category and Tag pages, and will really help the site's SEO too!
https://www.firstep.co.uk/work/category/Web+Design
One problem I had with the latest version is that it caused the first blocks of text on the main article pages to disappear. I fixed this by pasting the code into a Code block at the bottom of the Category page, rather than the Header Code Injection that is applied to all blog pages.