Lets say I have 5 files in a privat folder, 
and I add tags and comments to it for better organisation & search possibilities.

Now I copy this folder into a group:
Unfortunately the metadata (comments, EXIF, tags) of the folder and containing files is not copied to the group.

It would be nice to have the possibility to copy the metadata as well.
Or to allow a linking of metadata between the same file in different locations.
So that the metadata gets changed on all file-locations if someone adds a comment, etc.