There is [a user script for SE chat](https://github.com/TehFlaminTaco/TacosUserscripts/raw/master/caretreply.user.js) that allows one to mark one's chat message as a reply to the previous chat message by beginning one's message with `^`, the second-to-last message by prefixing with `^^`, etc. This would be really nice to have on TA, so one doesn't need to click to reply.