[RaftPeople]

I don't use these apps so maybe my solution wouldn't work, but after reading the article, it seems that having a visual indicator of messages that are new but in the past would be a reasonable solution.

Especially if there were simple controls to flip into a mode that minimizes the ones already seen (collapsed and grey for example) while highlighting all of the ones inserted in the past.

Or, if there are many messages already seen and few inserted into hist, show the inserted ones with a small sampling of the already seen (so the user can anchor to already familiar data in the timeline) along with "72 messages hidden that were previously seen" type of thing in between the inserteds to condense the view.