Hi Frank,
If you are seeing inconsistent behavior with the Update and Add to Workspace functionality or with the config.pro options used in conjunction with Windchill then that should be investigated by PTC. Were cases ever opened for this?
In general, Update should update out-of-date objects (i.e. there is a newer version on the server because someone else checked it in while the user had it in their workspace). Add to Workspace should let you bring in other non-out-of-date files, where you can either reuse the content already in the workspace or overwrite it. Workspace synchronize will update metadata changes (lifecycles, etc.) from the server.
If that's not happening then it would be good to investigate the use cases you are seeing to figure out why.