Update: Document Sets in Modern Document Libraries

JanKlooster , One way I found to move document set between librairies is to create a folder into the source library, move the document sets into the folder. Then you can move the folder into another library (document set content type needs to be available) and then you can move the documents sets inside the folder at the root of the library.

UPDATE: I found however that the document set metadata does not get transfered. It sets back to folder (even if we see the document set icon). Need to set the content type back to document set and fill the metadata.