Jump to [1] isn't styled, maybe that's something you can look into?
What do you think otherwise? I’m a big fan of betterslack :)
I really liked how you avoided doing any JS at all :)
One thing I'd like to propose is making it wider.
I'd really love to add the markdown links from BetterSlack, but I worry that is more likely to anger Slack, since it would be introducing JavaScript.