I found this link to PDF test on an Quark FB page:
https://pdf-aktuell.ch/pa/language/en/disastrous-pdf-x-4-compatibility-with-new-affinity-publisher/?fbclid=IwAR3RmRuzr2-OpoZe0z4PNKRlJ83mqilHNJjGgQ1kv-zVwUWbcHs_Vwpifns
The goal of 100% passing the GHENT Test Suite is not only desirable it should happen. But it cannot happen until pdf passthrough is available and may not be 100% possible using the pdf library Serif uses...Serif wasn't able to do so using an older version of the same library in the Plus line anyway.
I fully understand the various GHENT tests.
As regards the "any application will fail" comment, that was in relation to any application that is opening a GHENT test pdf for editing. They w