The paper explains it more as an experimental process than a manufacturing process. Each granule of hiroshimaite captures a "unique" micro-environment. One could imagine an ethical version of this involving conventional explosives in a controlled environment containing a variety of metallic samples of different compositions.

Metals refining in space or a no atmosphere place like the moon. If an alloy is discovered that has properties we want I can see some future civilization popping nukes like pellets to produce it.

Using conventional explosives is a real thing that exists: https://en.wikipedia.org/wiki/Explosion_welding