The XB-1, the 1/3 scale model, uses standard General Electric J85 engines.[1] Old, reliable, not too expensive, and used by many prototypes over many decades.
It echoes my criticism of Virgin Galactic checks notes ten years ago.
That said, Boom started dancing with the DoD in ‘22. That’s a deep pot of cash, and could help make up for inexperience.
A couple billion bucks is pocket change to the DoD, they literally "lose" it in their couch cushions, and it could eventually be the difference between "viable domestic defense aerospace industry" and "buy threaded steel nuts for $9000 each, with an 18 month lead time and 5000 pages of paperwork."
Hahahaha. No.
That China still has trouble is one thing. The fact that Russia also has issues, with around 80 years of experience, tells you everything you need to know about how non trivial the task is.