We could pipe in audio from Neil deGrasse Tyson over the First Order’s or Resistance’s intercoms explaining that one star has the power to destroy ten thousand planets.
But yes, the idea is that, apparently, one star does not equal one firing. And as far as this edit goes, there’s nothing to say that it wasn’t built for a single-use against Capital Planet.
That’s all fair enough, since the edits changes any assumptions of a one charge up per fire.
Or like you said, you can easily put in that quote. Maybe get a group of people in First Order troops in a class room with a sign that says “StarKiller Base 101.”
I see no flaw!