The description of transplutonic ore/metal appears to be wrong. I'm not an expert I'm just gleaning this from wikipedia. Maybe this is an argument for just calling it Rare Metal.
Refined heavy and exotic elements including rare earths, actinides, and more exotic elements essential to advanced industrial and research applications.
Transplutonic means with a higher atomic number than plutonium (Z = 94)
rare earths: Z = 21-71
These are not transplutonicactinides: Z = 89 - 103 These are fine
more exotic elements: Vague is always safe; these are fine.
It's fine if sci-fi makes up new terms. But I don't see the point of taking a real term, which this is
citation, and using it incorrectly. Starsector already does this with 'mothball' and 'skeleton crew,' and it's annoying.