[matthberg]

Looks different, from that docs page they're using a mix of:

- ZeroWidthSpace,

- zwj (zero width joiner, used with emoji modifiers like skin tones),

- zwnj (zero width non-joiner, used to prevent automatic ligature substitution), and

- U+FEFF (zero width no-break space)

It's a clever system, thanks for sharing the link to it!