The Army contract isn't quite as portrayed. Fact is, the Army didn't select Cyclone to build a prototype; they selected another company with a different engine. Cyclone bought the other company so as to get the contract and substituted their own design.
Given that the engine was delivered and the news release followed almost instantly that the engine had been tested in a dyno cell and met the requirements, it follows that they only did a cursory test to see if it delivered the correct amount of power. It takes weeks to months of dyno testing and multiple engines to do a valid testing program to industry standards so as to verify economy, durability, reliability and so on, not a day or so on one engine. Cyclone's own press release stated they were pursuing further contracts to improve the design for manufacturing and durability. An essentially unproven design that by it's own builders admission lacks the needed refinement to facilitate production and reliability is going to be hard pressed to get orders if any viable alternatives exist.
