> The undeniably correct way to render it is with two minus signs[1] and absolutely not something non-ascii.

> [1] Not strictly a hyphen, which has its own unicode point (0x2010) outside of ascii. Unicode embraced the ambiguity by calling this point (0x2d) "HYPHEN-MINUS" formally, but really its only unique typographic usage is to represent subtraction.

Strictly, its as you note, the hyphen-minus, and Unicode has separate, disambiguated code points for both hyphen (0x2010) and minus (0x2212); hyphen-minus has no "unique typographic usage".