Attributes like "regex" and "case-sensitive" should be retrievable with the $highlight() identifier.
So should the rest of the information that belongs to each highlight item.

Also "nicks" seems to signal that either "both" or "Nickname" is selected in the "Match on:" dropdown. But which one of both it is, is unclear. That feels inconsistent somehow.

They should be and are retrievable just not documented.

$highlight(N).regex
$highlight(N).cs

Ah, good to know. Then I'd still like them to be added to the documentation