Here is the solution:
Hi, I am looking to buy a bunch of cladding for a high rise building, look can I get a test piece independently tested by my chosen choice of testers?
See my wife worked for a Viet exporter of clothing that ships to the UK and other western countries. A container of clothing does not ship until third party testing is performed on test garments.
So, you have a test room where workers will make the perfect item of clothing, it then goes to testing. By this point the container is sitting at the dock. If the test fails, item out of spec, that container won't move.
So this concept that your going to buy cladding and not bother to have it independently tested yourself before shipping it, is crazy.