it is possible to prevent the “Copied (replaced existing)”. i believe that dropbox allows the file to be duplicated and that it is stored multiple times under the same name. if i then download the file under rclone i partly have a different checksum than if i download it via http directly from dropbox. I can’t replicate this every time it’s kind of random.
-c, --checksum Skip based on checksum & size, not mod-time & size