Good luck to 'em. But I don't know that I would have picked several never-flown techniques as the basis for my least-cost rocket. I count at least four: aerospike nozzle, methane fuel, autogenous pressurization (whatever they mean by that), and all-composite structure. That would seem to be a path to spending lots of time and money on research.

To be fair, composites and aerospikes are well-tested, and methane has some good qualities and no obvious problems as a rocket fuel. (I don't know what they intend for pressurization; perhaps they want to boil both fuel and oxidizer to create pressure? Seem like a non-standard technique anyway.) And it's not like you can buy rocket hardware OTS, so everything you do is a development project. But none has flown on a real vehicle. Picking one would be ambitious. Four just seems like compounded risk.

Scaled Composites has had plenty of trouble with their seemingly-simple hybrid engine. You may think a technology is researched enough or simple enough to use without much danger, but rocketry is an extreme environment and can hold lots of surprises at scale and in the margins.

SpaceX, on the other hand, has only done one really revolutionary thing: cost discipline. Mostly through simplicity. Which is a pretty important contribution to the world of rocketry. Much more important than any particular nozzle or engine improvement.

The Firefly Alpha should be a nifty rocket if they can get it flying without spending too much money--but the history of rocket development doesn't suggest that'll be easy.