That is an interesting thought. Perhaps it is possible to arrange a type of nested structuring when this is needed. Like a CSV inside a value. C for "control code separated" of course :-)
Very thought inducing... I think the main impediment is that these characters are not visible and not so easy to type. If they were, we might not have got the number of CSV variants that have evolved.
What I'd want is an emacs special mode, that displays RS as a red* comma, GS as a simple newline, US as a red semicolon, and regular newline as a red "\n".
Comma, newline, and semicolon insert the control characters, while M-, etc insert the literal characters. Not sure exactly how to handle header lines but this is the general premise.
*red as in "whatever method of visually distinguishing them as special works for you"
Very thought inducing... I think the main impediment is that these characters are not visible and not so easy to type. If they were, we might not have got the number of CSV variants that have evolved.