If you want to save document changes back to the database, you'll need to re-insert the documents into the container fields after saving the changes to disk. The database still has the old version otherwise.
I doubt my users can be relied on to do that, as sensible as your suggestion is.
If they could open the file from its location (open storage) via a scripted button, then any changes they make should be saved just by closing the file (say MS Word) and saving.
I can't imagine this is an uncommon challenge.
I have just watched the webinar about containers and now realise that if one were to open the file from the remote storage location and change it, it would then be considered a "tampered with" file.
Therefore I guess I am asking for something that can't be done.
So, I guess your method is the one I will go with. Much appreciated. Just have to train the users as it is a bit tricky.