I don't have any expertise here, but I don't really see anything in the article to support the idea that the problems are fundamental. That's certainly the conc

I don't have any expertise here, but I don't really see anything in the article to support the idea that the problems are fundamental. That's certainly the conclusion their experts come to, but it all seems to be based on looking at the proposed technique and poking holes in the assumptions. There are all these problems, and while they have solutions, the solutions are expensive. Ok, but maybe there's another technique that's better. We can't think of one right now, and maybe we never will, but it's not in the same class of impossible as faster-than-light travel. It's more like fusion power: the engineering is too hard. The article is pretty persuasive on the lesser claim though - all this enthusiasm is unwarranted, and we shouldn't invest heavily.