I mean, I’m totally open to redo any line if Nev or the community prefer.
The reason I liked “kyber” is mainly because it makes Starkiller’s link to Ilum that much closer, and it’s a nice tie to Rogue One and other recent canon that makes kyber more of a thing.
Going down the headcanon rabbit hole, you could even use the modern idea about lightsaber (kyber) crystal ‘bleeding’ to explain why the beam is red rather than the Death Star’s green (which could then take you even further down the rabbit hole of asking how powerful a Sith you’d need to ‘bleed’ a planet of kyber).
Plus, I think having it described as something unfamiliar and distinct helps it flow nicely with Snap’s next line about not knowing what to call it.