What is the single biggest technical risk?

On the electricity side, the biggest single risk is the burner's plug-density requirement (n_p/n_c ≈ 16): net power depends on it, and it must be demonstrated. Kronos labels the burner's net power requirement-class for exactly this reason, and the breeder's value does not depend on it.

Naming it as the top risk is part of the honesty framework.