I created a panorama from three photos while not connected with my file server, so the pano was created as "Smart-Preview_Pano.dng" file. Now after reconnecting to my file server I have access to the full resolution files and I would like to convert my smart-preview-pano (which obviously is lo-res) into a full-res version using my original files. Is there a way to do this, keeping all my settings & edits I made when creating the original smart-preview-pano?
You can't convert, but it's still easy. Create the pano again from the full images, then sync all edits between the smart preview pano and the full res pano. The only edits you'll have to redo are things like spot removal.