At the moment, if I want to look at the activity of a thread I've already read (new Answers, new Comments, new Answer/Question edits), I have to go through a tedious process. Luckily, we got a lastactivity button, but that only shows the latest activity:
By sequential activity, I mean a list of links sorted by latest activity first.
The reason I want this feature is because I often want to know what activity I missed. In my case, this is on threads I've Starred, in which I don't wanna miss a thing. It's easy to miss stuff when relying on lastactivity, especially on busy and/or large threads.
UPDATE: Good to know such a feature exists, but it would nice if it was easily accessible. An example would be the following, where history links to that activity:
active: 8 months ago (history)
/posts/<postid>/timeline
give you what you want?