A PIF maximum of 10x at 8ECC scanning?
U need to spend more time in the Media forums or perhaps .... Are you a virgo? They're supposed to be perfectionists
It could easily be that you got 1-2 PIF for each sample in the 8ECC block, or more to the point, an average of 1.25 PIF for each sample in your little 10 PIF molehill, which you consider a mountain.
The chance that you get a 4 or higher peak is pretty low, especially when the majority of those 8ECC PIF levels are well-under 4, meaning an average of less than 0.5 per sample.
The fact that your PI is so low & your PIF is also less than 16, suggests those discs are fine & have just have no idea how to read these graphs.