It's one thing to write code with Unicode characters like ≢. That should be fine, and it's not difficult for programming languages to support it. (You could roll your own preprocessing tool).
Doing it with ligatures is not a great idea, because ligatures are a PITA (not always well supported) and add too much incidental complexity.
Doing it with ligatures is not a great idea, because ligatures are a PITA (not always well supported) and add too much incidental complexity.