If an Entry represents some file/resource that has changed – is it enough to change the updated field? I note that most feed readers won’t show it as "new" as it has the same UUID?
RFC 4287 says that I can change it, but feed readers seem to ignore it.
Well from looking at this, RFC 4287 says it’s fine to update a resource and its updated field. However, if you want feed readers to pick it up as a fresh item – you need to think of an Entry representing a change, not so much 1 to 1 with an underlying resource.