Like mentioned in the linked answer from @MarkO'Connor it seems that properties are the way to go.
Here is a related Question/Answer (again from @MarkO'Connor) on how to handle those Properties
https://stackoverflow.com/a/3079655/1756183
So i will distribute a common version.properties file together with the already common ivysettings.xml to all Projects. This way the default ref will be filled with the version property placeholder and can be overriden with a specific version if needed.
It's not as charming as the dependencyManagement from maven (where i just can omit the version) but i don't see other solutions, do you?