What do you guys think about a menuentry for folders to update only all feeds that is located in that folder? There is a menuentry for "Refresh all feeds" which refreshes all feeds that are registered in RSSyl - how about a possibility to refresh only a subset of the feeds? Using folders to group feeds that are similar in content, it might be a good idea to be able to refresh only this subset of all feeds.
This is already possible in my RSSyl rewrite, and you can help bringing it closer to the release by testing it. See http://lists.claws-mail.org/pipermail/devel/2012-January/000201.html
Since integration in master branch of the rewritten version there's a “Refresh recursively” option on every folder, so this is now fixed :-)