Looks good but have you considered something like reddit bubble, you can scroll all replies without closing editor. I like Blorp better but reddit bubble is very convenient.
Also when there is draft comment, if not troublesome add some indicator that there is draft on reply button.
At first I was surprised when I used Blorp how to reply for main post and took me embarrassingly log to figure out you write it on bottom, suggestion add also reply button to post similar to when you reply to comment.
Is summit foss?
On its github there is no license.