With a fresh oil analysis and a trend analysis series, you can already see how an engine oil performed. You have to pay attention to what an analysis can show you. It cannot show coking or compatibility with seals, for example. Make an analysis immediately after changing the oil from the engine, and always according to identical mileage. If their driving conditions are almost identical, you can already see how an oil in the engine works in terms of wear. Where else should the elements such as iron and aluminum come from, if you know the initial value after an oil change, then these are from wear and tear. It is only important to drive or compare several analyses with the same oil.
Spectrography only samples a narrow range of particle sizes, so if the engine is shedding larger particles, the testing is "blind" to that. That's why it often doesn't catch rapidly occurring failures.
On top of that, it can't differentiate between corrosion, wear, chelation...etc. So if you have an oil that has aggressive chemistry, it can show higher levels of a metal in a UOA, despite quite possibly producing lower wear.
An additional point is that an oil with a weak DI package that's allowing deposits to form can show artificially low numbers because metals are heavy and are more inclined to fall out of suspension and get caught in these deposits. Contrarily, an oil with aggressive chemistry may liberate these metals, artificially inflating numbers.
This is why UOA's aren't meant to be a comparative platform for different lubricants, they are a mechanism to, firstly, let you know that the lubricant is still serviceable and, secondly, whether it's contaminated with something that should cause cessation of operation until this can be remedied, such as coolant ingress, significant fuel, air intake tract leaks...etc.
And then of course there's the accuracy, which we know can be all over the map, even with the same lab.