It's definitely tracked, I've taken a look at some of my comments on Lemmy and it has an indicator if I edited them. I think kbin just doesn't have the UI for it yet, but hopefully it can be added.

None of the apps have an indication, but it would be nice to have. I can just go and make people look silly by changing things and nobody would be the wiser :p

I use Jerboa (for Lemmy) and there's a parenthesis right next to the timestamp that indicates when the post/comment was edited.

Afaik kbin doesn't have any indication of such. The etiquette is to put a note when you edit your comment.

Reddit doesn't always put the edit/asterisk mark when someone edits. Rather, it gives a small time period (maybe 5 minutes) to "shadow" edit your comment, without any notification being made. This is to allow quick corrections/typos and the like, without getting marked as an edited comment. then later edits are marked by the system (even if you don't mention the edit).

Reddit's system, combined with a system I see often (on twitter and reddit) where you can see previous versions of the comment, I think are ideal. That way you can see that it's edited, what the previous version was, etc. but also still grant that typos happen without permanently marking something as edited.

Since kbin uses activitypub, I'm actually not sure how the edit feature works here on the fediverse. I know it's possible to edit, but how does syncing with that work?