Does the Copy command under virtuoso place db objects into a "paste" buffer that is still maintained after the copy command is terminated which could be accessed with a SKILL command some amount of time later ? Is the buffer erased and filled with a new object once the copy command is started again ? Is there a history associated with copy that I can see ?
There is no paste buffer used by any of the copies, the interactive ones copy the elements in the selected set, the SKILL one copies one object at a time.
The interactive commands may leave you with a set of selected elements, I forget if they are the pre-copied elements or the new copies. You could save the selected elements as a named set and then recall them to copy again if you were doing this interactively.