Well my point being that no one is looking at additive amounts, you are looking at certain mostly metallic elements from decomposed compounds. You can make a few "tea leaves" assumptions about the origin of some of those elements, but there are additives that aren't composed of metallic or tested elements. That's why licenses, certifications and approvals are based on a battery of definitive tests for everything from wear to oxidation resistance to 20 other things. No license, specification nor approval is based on a cheap spectrographic analysis but on much more representative tests.
Yes that's what everybody else looks at but nearly every time they are drawing wholly unwarranted conclusions. Go look at the Afton Specification Handbook and see what goes into every approval and license, even the widely disparaged API license. See how many of the requirements are based on a spectrographic analysis.