SSO users can now use SSH keys to run one-off dynos in Shield Private Spaces
Change effective on 14 September 2018
End users of SSO for Heroku can now manage and use SSH keys on Heroku for the specific purpose of running one-off dynos for apps in Shield Private Spaces.
Note that even after adding an SSH key, SSO users can not use it for general authentication. SSO users can only authenticate with Heroku via an active SSO session.