It's pretty mind boggling indeed. Back in 2005 I did an internship with one of the two manufacturers of lithography lensing systems, in their R&D. It was very interesting and certainly showed me that my physics studies weren't really teaching me optics at all.

Weird anecdotes: the people working on EUV didn't believe in it at all. It was a big joke to them. But the roadmaps were showing it... not in 2019. The mirrors were being polished by hand. Robotic tools are more accurate, but the inaccuracies they produce are aligned, creating optically meaningful patterns. So instead they had two guys with PhDs in metallurgy polishing mirrors. The all important simulations of lensing systems were done with classical optics and a ton of FORTRAN. Certainly throwing in some phenomenology around effects that are ultimately quantum effects, but no out there quantum optics or anything of the sort. This was 2005 though. The weight of the lenses itself changed their optical properties enough that we would measure the stresses induced by their weight and the impact on optical properties so we could include that in the system end to end error budget.