Bleh

That said, it'd be nice if it could collapse the posts above the highlighted replies, rather than nesting everything and you having to scroll down to find them. But again, this is no different to scrolling down a tl;dr discussion in the normal talk page manner so it's more a problem that it doesn't solve than a problem it creates.

Isn't that what the arrow does? (Which should be a lot smaller and maybe down the bottom of the comment)

No, it just seems that clicking the arrow above a nest of comments collapses the whole thing into an outline of peoples sigs.

It's also messed up for me doing that, showing just a repeat of the same sigs over and over again. Unless you and I have had a conversation in this thread with 100 posts apiece without me noticing.

The repetition is obviously a bug. It is suppose to fold so you can see the next reply to the comment.