Hi @Pablo,
Here is the permission level users need to copy/move the files to a new target location in SharePoint.
The users need at least the "Contribute" permission level so that they can copy/move files. But if the users have "Contribute" permission level, they can download files from the document library.
So in this scenario, I'm afraid it is impossible to allow users to be able to create their own versions of the PowerPoints. If the users can create their own versions, they must copy/move the files from the source document library. The result is as I said above, they can definitely download the files in the target library.
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