RSS fundamentally has this problem, because it does not identify posts uniquely, so RSS readers have to guess at what new things are the same as old things. (The URL is usually a sufficient key, but that doesn’t work here because LW changes the non-lookup-key “slug” when the post changes.) LW should switch to using the Atom feed format which has a field for unique post identifiers.
RSS fundamentally has this problem, because it does not identify posts uniquely, so RSS readers have to guess at what new things are the same as old things. (The URL is usually a sufficient key, but that doesn’t work here because LW changes the non-lookup-key “slug” when the post changes.) LW should switch to using the Atom feed format which has a field for unique post identifiers.