Another quick comment on this specific question. Collections / institutions and the people within - collection managers, data managers, “the person in IT who exports the DwCA archive out of the collection management system” all need to know about the identifiers applied to their collections - particularly if they’re not the ones actually creating these identifiers. If ‘your’ collection appears in GRSciColl, the ALA Collectory and the GBIF Registry all with different identifiers that you’ve never seen before or had any hand in generating, why would make you use any of them? And which one would you choose?