We had some code lying around to put links on each post to jump to the next or previous post. It wasn’t live because it still needs some work, namely it needs to skip over collapsed posts. But while using a trackball without a scroll wheel today I quickly dusted it off and pushed it live to make it easier to peruse the topic pages.
It still really needs to be able to skip collapsed posts to work well, but is something I found useful enough as is to push live. Give it a try.