CNC Mill Mark Removal in Intake Port

I was going to ask you earlier about this. What would you say your machine is capable of for precision and repeatable accuracy for the CFM measurement? For instance can it determine to a tenth (0.1) of cfm? Then for a test repeated on the same port under same conditions say five times stepping through the lift range, what would you expect to see for variation for at a given lift number? I'm just trying to baseline the changes I see people reporting, vs machine capability. Changing something that on the next run results in a 10 CFM change may or may not be reality. I am/was an engineer and know that when examining test data, the capability of the measurement system needs to be factored into the analysis.
No way can this machine (a Superflow 300/600) accurately determine 0.1 cfm. I'll stick to my 1/2/3 cfm story from before. If I were to run back to back tests within a few minutes of each other, I would expect 2-3 cfm of repeatability. There are so many factors that can influence results. Air temp & humidity. Bench temperature. Rigidity of valve opening device. Accuracy of valve opening device. Vacuum motor bearing and brushes. Then there's the entry plate or clay situation. If it was removed, is it back on exactly as before?

For most applications, the 2-3 cfm accuracy (less than 1% of full range) is good enough.