I once tried to make groups as npubs, nostr:nprofile1qyvhwumn8ghj76r0v3kxymmy9ehx7um5wgcjucm0d5hszrnhwden5te0dehhxtnvdakz7qg3waehxw309ahx7um5wgh8w6twv5hszymhwden5te0wp6hyurvv4cxzeewv4ej7qg6waehxw309ac8junpd45kgtnxd9shg6npvchxxmmd9uq3camnwvaz7tmrdphhyatn9ekkj6m9v35kcem9wghxxmmd9uq3camnwvaz7tmrda6kuarjd9jhxtnxd9shg6npvchxxmmd9uq32amnwvaz7tmjv4kxz7fwv3sk6atn9e5k7tcqypaaaaa7ytwcuk05vq8qgj498gw0jadfm37j0h6cxw780kmcffvq2875gre  proposed products as npubs, someone proposed forms as npubs, and (in my opinion) none of them really was a good fit. Stuff that's domain specific should be domain specific (even if there is a key tied to the alternative metadata event).