The videos that you provide suggest that to create a new set of Annotation Groups one should copy the dgnlibs provided.
But the dgnlib contains so much more than Annotation Groups (Element Templates, Feature Definitions etc.). So if I did copy the original dgnlib I would have 2 sets of Element Templates etc. named the same, and eventually that could become a problem if definitions should be updated.
So I tried importing an Annotation Group with a new name into an empty file, to keep it as clean as possible, but it did not really work. The Named-Boundary-Drawing-setup used the original Annotation Group - even though I picked the new one.
So what is really necessary to have in a separate Annotation-Group-dgnlib for it to work?