Surely just an oversight, but I just wasted a lot of time generating an addin that would write the sync version of linked revit models into a special marker family which now reads (SyncVersion available via API). Change that.
Why would others need that? Well in campus situation where a lot of designers, modellers work on each of the buildings it is useful to know which of these have seen a lot of work (supposing people sync when they've done something on the model) and which ones have only just been setup.