I think the easiest way would be to create a separate HTML page for the updates and add microformats for note posts. Then plug that URL in to Granary (https://granary.io/?x=118&y=19&input=html#logins) and convert it to RSS. Granary will give you an RSS URL that people can subscribe to in a reader. That way you don't have to mess with RSS and XML, which can be messy. I do this for the feed of my notes: https://gregorlove.com/notes.atom redirects to the Granary magic and voila!