The closed issue http://tracker.moodle.org/browse/MDL-7277 contained the request on handling a link on external imsmanifest.xml files as part of SCORM packages.
It is not quite clear if this feature can't be realized. The discussion in this topic showed that it is not possible to upload the imsmanifest.xml file. Thats clear because the links in the manifest are relatives. But what about a solution of only linking to an imsmanisfst without uploading.

There are two situations we need such a function:

• avoid copies of SCORM packages
• SCORM packages with time based licences by publishers.