We are implementing ProCSS publishing by ourselves and knowledge from ProCSS is badly available.
Hi Antti, We noticed that some of our content on the Knowledge Center was hard to find, so we're restructuring our KC. This will also include the complete Publishing section, including PDF ProCSS.
The current link for PDF ProCSS is https://kc.author-it.com/reader/dBoJlPM5GErMmZGR2~O17Q/rduOMatvhi0vyqGYF8WLUg
Please expect an update soon.