Thanks for the pointer. Unfortunately I do not monitor every thread (life is way too short

) so I confess I missed that.
What I'm missing in your & Chaley's discussion is the intended net result on the Kobo side: IAW what is Kobo supposed to show on its collections pages after using the templates? A screen dump would be helpful.
I know, you and Chaley can certainly dream in Python code and do have intimate knowledge about calibre's inner works: being a mere mortal, I cannot.