You’ve missed the point of the article, which is that optimising for code point indexing is silly. The author is well aware of all the properties you speak of,

You’ve missed the point of the article, which is that optimising for code point indexing is silly. The author is well aware of all the properties you speak of, but they’re seldom things that end-developers should be touching directly, and none of them benefit from indexing by code point offset.