Think 'boxes in boxes' to get maximum insulation. I also have a friend who works in this industry and he once joked that they have an almanac built in to deal with moon tides and while it is a funny joke you have to wonder if there isn't going to be a time when even that sort of effect will have to be accounted for. Amazing stuff.
ASML is one of a short list of Dutch companies that I'm super proud of, they keep on innovating no matter how extreme the challenges are. The moat they have is incredibly deep.
[1]: https://arstechnica.com/science/2020/07/ligo-is-so-sensitive...
Alternatives were tried. Synchrotron EUV sources. (works, but huge). Linear accelerators (The SLAC beamline was used as a light source as a test). X-ray lasers (don't work yet). Electron beam lithography (works, but too slow.)
There's got to be a better way to do this.
EUV masks are made that way, slowly.