The new Domino One Touch setup is awesome!
For test environments it would be a very cool addition to cross certify on the fly with an existing ID. This could be an Admin safe.ID or or Org safe.ID.
Once we have a cross certificate, it would be also important to add the user as an administrator.
From security point of view this should be OK. The cert.id is created, ID Vault is created. So a cross cert should be also fine.