Expand only new comments in a thread
We often have threads that get fairly long, 40+ replies. When this happens, it would be nice to be able to only expand the comments section to show the new comments.
So say you have 56 replies to a thread, and while you are working on something else 7 new replies get added. If when you return to the thread it is collapsed to only show the most recent comment, you only have the option to expand to show all replies. This means that you have to scroll through the 56 old replies that you have already read in order to reach the 7 new ones at the bottom that you need to read. If the system either let you expand only to show the new replies OR auto focused on the oldest "new" reply, that would make using the system in these circumstances much easier.
Possibly a separate item, but the ability to collapse these threads from the bottom of the thread would also be useful, but a quick work around is to simply move between channels so everything re-collapses.