/ignore -h would be nice, which stops certain people from triggering your highlight system.

agree

signed.

Maybe also an event that triggers at the same time.. ON HIGHLIGHT.. ?

Hum, this event might coincide with other events, so my opinion about it is ambiguous
At the moment, you could use something like: on text / action > if ($count($1-, [ $highlight($1-) ] )) { stuff } ... but that's not inerrant, notably if using vars, identifiers, regexes for matchtext...
I'm thinking about a "$ishiglight" identifier for on text/action events instead... or even a operator "ishiglight" for if-then-else statements?

mm.. good point.