I like to read entries in chrono order. If I end up at the top of the stream I want to get back to where I was without needing to scroll, wait, scroll, wait. If it’s been a while that process can take forever.
Click to mark position when I leave? Automatically mark when a post scrolls into my view as I go?
Ok, how about to the last item I liked or commented on? I get those in my My Activity list. Some way to click on a discussion and jump to it in the stream.