Hi Nicolas,
Edwin’s coworker here…providing an update for community awareness.
We did make #1 work properly. #2 is still evading us. We have also opened a support ticket and linked this post to it. What is unclear right now is the fact that SAML Enterprise Connection allows for SAML Single Logout URL but it doesn’t seem to be used or we yet to find a way to make Auth0 use it.
If we get any further traction on the support ticket, we will update this post with a solution.