I'm always amazed and impressed by the people who work on these giant projects. To do all that engineering without really knowing if it'll even work in the end must require a huge amount of confidence in both yourself and the rest of the team.

Confidence, or conscious willingness to take steps to unknown (will to explore)?

Furthermore, if the technology works eventually, you may already be retired (if not passed away!) In my opinion, the motivation rather comes from the fascinating scientific questions behind those projects. Whether it works as an industry may be "just a plus". Disclaimer: did a phd in tokamaks / experimental data crunching

Well, even if it ends up not working, you learned a lot along the way. Ambitious engineering efforts are never completely wasted.

Maybe this is pedantic but it does look like it has fivefold rotational symmetry, which makes it a lot more regular than a typical car body, for example. Still, complex geometry.

Yeah, it was probably something symmetrical in the laws that allowed them to simulate only single part of the coil - saving the computing time and lowering the search space, stacking up resulted in full coil.

I'm not sure about the laws you refer to. It seems to me that the constraint is that for a twisting ribbon-like plasma they had to have an integral number of twists or half twists in a complete circuit, not twisting too sharply, not too gradually.