Thanks for the in-depth analysis. My misunderstanding was about what an identifier considers a number; I have no well-thought-out ideas on the subject of what an identifier ought to be.
Having the docs mention that "number" means only characters with a Unicode Property GeneralCategory of Nd might have prevented me from looking through the NumericTypes for a pattern. With more experimenting, I might have noticed that De was the one that always worked, since De has a one-to-one correspondence with Nd... -y
