A turbine engine may be the Ultimate "Omnivorous" engine.
In the near future it may not if you can get the fuel, but can you burn it.
Their are drawbacks, Without a recouperator to send the heat back through the engine, efficiencies are incredibly low.
Another problem. As a hobbyist, you probably could build a piston engine on a lathe and bridgeport and it will run, but I wouldn't try it with a gas turbine. But when it comes to balancing at the RPM's he is talking about, you need VERY expensive equipment. Another issue is liberation. Little engine parts breaking loose if not designed robustly enough are literally deadly, as they fly though the outer case at you.
If you can't tell, I spent some time in the arena, and that is as far as I go, but at this point consider me from Missouri....
"Detroit can do this tomorrow" ...Ya well there is a story about one manufacturer that tried that, auto tolerances and all.... the Proto engine burned up, IMHO I not think this gent has any real exposure to the gas turbine arena, it is not as easy at it looks....