Duplicating selected text (not complete paragraphs), with alerts for any subsequent edits

I want reproduce selected portions of text in a different part in the doc, and if the 'master' text is edited have the copies update automatically, or at least be alerted that the original text has changed.

Specific usage case: I am using it for a peculiar style of endnotes – rather than use numbered paragraphs the client wants to reproduce the relevant part of main text in endnotes and then provide the citation. Sometimes the quoted text will be an entire paragraph, but more typically it will only be a portion of a paragraph, and sometimes as little as a word. FWIW I this idea might be more broadly useful for pullquotes, where if the author edited the main text then the pull quote would be automatically updated, or at least there would be an alert that the relevant text had changed.

Suggested method seems to be to Create a hyperlink destination​ and then Insert a cross reference. My problem is that none of the Cross-Reference Formats seem to be useable. Partial Paragraph initially sounded the most promising, but it's very limited. The closest candidate is Text Anchor Name. (When creating a New Hyperlink Destination the selected text becomes the default name for that text anchor. Problem is the name field is limited to 100 characters, and often my selected text will exceed this).

Any ideas? Any scripting or plug-in options if it's not possible with regular tools?