It's like future technology that we are told is conventional technology. We think of a prop engine with gasoline, just in a more advanced shell... but this is technology that harvests power from the air (!!??) and requires no fuel? Just compressed air pulling and pushing the plane.
So the only reason there is a range limit is that it's not 100% efficient and would eventually run out of... no fuel... ability? There's so much that is not explained and kept from the public. There is so much to still understand.