So you wanted to take pictures of cdroms with a microscope, going on a decent detour and the other way you can make a microscope from a disc player which is a really cool project [0]

[0] "Hacking CD/DVD/Blu-ray for Biosensing" https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6066758/

This is basically how an optical CMM (OMM) works. There are tricks to determining and calibrating out alignment issues and determining snapshot viability, and you're touching on both of them. Very well done!

If you photograph and stitch a panorama of a CD at a resolution with the data visible and distribute it under your copyright, is it piracy?

Would be really cool to read a whole CD this way. Actually, that wouldn't sound any different. You could read an LP though.