Chat Highlight Settings in PRIVMSG Tags
Looking through the IRC Chat Tags, it doesn't appear as if there are tags that would trigger a highlighted message.
For instance, if a first-time chatter posts something in chat, it would be nice to have an IRC tag that indicates that they're a first-time chatter. Regardless of what the user has set up on the website, this would allow for a bot, or StreamElements custom widget, to detect the tag and do something with it (such as play an alert, or post a message in chat, etc).
At minimum, the following tags would be nice to have:
1) first time chatter
2) returning chatter
3) raider - this one might be tricky due to it being time-limited, however, I can think of a use case for this one where the tag stays until the end of the stream.
4) (optional) suspicious user. I can think of some amusing interactions here, though probably don't want to draw too much attention as users don't know if they're marked as suspicious in a particular chat.
Rest of the Highlight settings aren't as critical, since they already have tags (mod, subscriber, etc).
Per https://discuss.dev.twitch.tv/t/chat-highlight-in-privmsg-tags/45604 "first-msg" and "returning-chatter" already have tags. Reasons stated as to why raider isn't. Turns out, it's already implemented. Examples are shown here: https://dev.twitch.tv/docs/irc/tags/#privmsg-tags just wasn't in the list of tags above the examples.