How does the design process for these reactors work? How much design is done in simulation vs experimentally and how high-fidelity are the simulations?
Fusion machine design is a combination of hard-won experimental knowledge and theoretical guesswork. I'm skeptical of the current wave of fusion startups simply because they don't have the weight of the decades of experimental work that have gone into tokamak research. But hey, they might make a breakthough, who knows.