I see. You're assuming, and that's what matters as far as I'm concerned. Not that I question your insight, rather I'm not convinced that small drops in the reading speed are detectable during a Scandisc test, because of the way the interface works. But these small speed drops will appear in the TRT... because it was designed this way.

Allow me to give you a hint (no patronizing intended) about testing optical media and conclusions that one reaches: keep the assumptions as scarse as possible, and reality-check as much as you can. - I've also been assuming a lot when I first started testing, and this has lead me to numerous mistakes, some of which were dramatically foolish .

I'm still not saying that you cannot be right about this, just that as it seems to contradict my own experience with TRTs and Scandisc, I have my doubts until I'm shown some actual graphs backing this up.