ok, so let review what we have:

if discs burned at 8X and 40X are identical, then i do not think we need to do experiements, since the 2 are identical.

the question now is that, with the difference caused by burning at 8X and 40X, which disc will do better in the aging/light exposure tests.

(i can gave some hypothesis to either side, but at the end thise will primarily be affected dy disc/burner quality)