This is very interesting. We've been bounced through Trello/Asana/HipChat/Slack quite a bit, and definitely experience this problem.

Curious - how well does it support chat contexts not associated with tasks? Like general or subject-based group chat?

Also - one of Slack's major advantages is it works great everywhere (web/desktop/mobile). Attaching task tracking to a mobile chat app seems like an incredibly difficult UI/UX problem.