I would be interested in using a category RSS feed which is ordered by the latest post per topic. It would still have one RSS item per topic, but the date/author/description of that item would relate to the latest post.
Here is what I’ve observed on my own forum:
/latestpage is ordered by the date of the latest post per topic, whereas the
/latest.rssRSS feed is ordered by the first post per topic.
c/category-name/category-idpage is ordered by the date of the latest post per topic in that category, whereas the
/c/category-name/category-id.rssRSS feed is ordered by the first post per topic in that category.
(The RSS feeds also return the author and content of the first post per topic.)
I’m putting this in the meta “bug” category, though I accept that there may be a good reason for it being implemented this way (and it may be that my observations are wrong).