I've really never seen in all my Gmod years any addon that could do that.
That being said, I think you've just come up with a basis for one of the greatest suggestions for update to Advanced Duplicator in a long time.
Seems the basis to have a server side spawn of an advanced duplicator save file at startup of a specific map using specified co-ordinates shouldn't be too far out of reach for Advanced Dup.
It already has the co-ordinates and height stored in the save file... having a server side load of that file hopefully wouldn't be overly difficult to do.
Is SpaceTec still maintaining Advanced Duplicator? He'd be the one to ask.