Small nitpick: the example "LATIN SMALL LETTER SHARP S (“ß” U+00DF) uppercases to the two-character sequence “SS”:³ Straße ⇒ STRASSE" is slightly wrong, it seems to me, as we now do actually have a uppercase version of that, so it should uppercase to "Latin Capital Letter Sharp S" (U+1E9E).
The double-S thing is still widely used, though.