Currently editing a comment at any point after you submit it adds the “Edited” note next to it. I find myself writing comments, submitting them, realising I have slightly misspelt a card name causing the pop-up formatting to not function correctly and then immediately editing the comment to fix the card name.
I haven’t really edited the comment to change what I have said, just fixed small typos. It would be nice if there was a 5-10 minute grace period after being submitted where editing a comment didn’t add the marker.
I think the actual solution here is for people who care whether a comment has been edited to stop caring about that.