Open version – as I understand its first when you have 2 or more versions of a flow I got the choice «open version». Thats logic but we use the url to «open version» for internal sharing of a flow because we don't want to use public link for this kind of sharing. It is then a problem that we're not able to share a flow with only one version, and we have to manually create a new version being able to choose «open version». With other words we like to see a version with read access to be shared and without edit mode.