This. I guess it would be useful to have this function even for arbitrary subthreads, perhaps as a link on each non-leaf comment that leads to a simple page like "recent comments", but local to specific post or subthread.
(There are already RSS feeds for comments on a specific post and even in a specific subthread (!), but not for on-site viewing. So I'm guessing one approach could be to generalize the mechanism of RSS feeds and have on-site pages corresponding to all feeds, with links near the current "Subscribe to RSS Feed".)
I'd also appreciate some kind of thread subscription feature. Currently I have (checks) 6 thread in my "check daily" folder that I ave to scroll through rapidly and hope I don't miss anything green.
This feature already works (probably, I never used it directly). Open a permalink to the root comment of a thread you wish to follow, and use "Subscribe to RSS Feed" link on the right to receive updates within that thread.
"Continue this thread" and "Comment score below threshold" could get a green glow if there are new comments behind the link.
An unthreaded version of Sort by New.