When working with non-roman scripts, projects have a choice between ASCII digits (1, 2, 3, …) and script specific digits (such as U+0660 ARABIC-INDIC DIGIT ZERO or U+0966 DEVANAGARI DIGIT ZERO). Unicode has more examples.
Some software products can be configured to use the script specific digits. In other cases I have seen requests for fonts to display script specific digits while using the ASCII digit codepoints. One font I know of (Noto Sans Oriya) has user features to toggle between ASCII and script specific digits, regardless of the underlying code point used.
Are such user font features (as in Noto Sans Oriya) useful for fonts? Or is the application support good enough to handle all the cases of script specific digits (verses, chapters, headings, page number, table of contents, references (such as see Figure #))?