Why is posts per page limited to just 40? It's only text being displayed and avatars which are cached so there's no bandwidth issues. It's a real pain when I want to search for some keywords within a 1000 post thread to have to click through pages one by one.
You can use "search thread" to search for the keywords.
And, to elaborate on that, if you know who posted the post you can search in the thread for that username and get their posts, from oldest to newest (by default) in that thread. Makes finding that obscure post reaaaally easy