If I read it correctly, an image of one of the slides says that it has been confirmed by 2 independent parties.

I kind of understand space agencies not trying these out. They are government funded with tight budgets. If they chased all of these and only 1% panned out, they would get lambasted by their ruling bodies as wasting money. Also where the inventor can’t explain how it works, it would make it really hard to support with the reliability we want in stuff we send to space.