You can LIKE a twitch comment to increase visibility
Add a button to LIKE a comment in chat. Add a little icon and number if a comment gets more likes. This makes it easy to see a good comment. (or change background color for a comments with likes)
Possibly, if a comment gets more than X LIKES, auto pin this comment for like 1 minute for visibility.
Good comments should be easily seen and interaction would be easy like this.