Re: It's a sure thing
Regarding your other question about production of 3He, there are 3 sources.
Fusion of Deuterium with itself has 2 outcomes of equal probability: Tritium and a proton, or 3He and a neutron. So they can use their reactor design, if it really works, with DD fuel and then refine / separate the outputs. This is likely to be a net negative power reactor, so the secondary D-3He reactor that follows not only has to break even on its own, but also make up for that pre-processing loss.
They can sell the Tritium to other fusion companies, or sit on it and wait for it to slowly decay into 3He (12 year half-life). That's the second way to source 3He. They could procure Tritium (difficult and super expensive) and wait for it to decay. Tritium is currently produced in very small amounts in specially prepared fission reactors and is proposed to be self-generated / recycled in some future fusion reactors not of the Helion design. Both of these require 6Li and neutrons.
There's more 3He on the Moon than on Earth (or at least we think it will be more easily procured there). However the efficiency of mining the Moon for resources to use back on Earth is rather questionable, not to mention many, many decades away. This is the only source which does not require machinery to endure a high neutron flux. Just cosmic rays...