The hydrogen paste – it sounds really cool, but unfortunately, the blow comes in the last sentence. The annual production of a new plant they are building will be 4 tonnes/year. US alone consumes > 3000litres (which is ~3t) of gas. Per person. So the output of the factory would suffice for one person in the US.
Yes, they will be able to scale. But the scale they need is hundreds of millions times more, more likely more than billion times more. I hope to be wrong, but I just can’t see how they could scale so much even in a decade or two.