I built this site's RSS feed so that it only includes the big daily posts, one per day, but that post is appended to throughout the day. This feels right for most people. It doesn't work if I want to crosspost, though, since the first published version is usually only me saying "Good morning" and that would be it.
I've added a second RSS feed, allposts.xml, which includes each individual post, independent of the containing day's post. I'll use this feed for crossposting. To keep things from becoming too noisy, I've added an attribute, "Crosspost" which defaults to false. Only those posts with $Crosspost==true are included in the feed. Clear as mud?