I don't have a particular need, but perhaps the CSV dialect should record whether the headings are considered to be case sensitive. Seems to be a flag supported by at least some CSV readers: http://joshclose.github.io/CsvHelper/
Or if not, perhaps the doc should indicate the standard position on case sensitivity, even if it's "case sensitivity of headers is undefined".
(Tiny unrelated issue: too late to change "doubleQuote" to something less ambiguous?)
@stevage great suggestion. Do you want to make a specific suggestion and a pull request?