Can somebody please clarify, that cookie sharing in Drupal 8 is just possible for sub domains siblings of the same parent domain.
Before this was discussed here: Multi-domain cookie - unfortunately just in a sub domain context.
To use the administration session of domain1.com on domain2.com is NOT possible due to security reasons (browser specific).
Or in other words: To be able to use the drupal8 administration area of content that is separated into 3 top level domains via the the "domain module" you must login 3 times.
Am I correct?