Thank you for your question.
Unfortunately today D2L doesn't offer the option to use an API or SSO with the IT Academy portals.
This feature has been placed high on the wish-list by our institutions, and I've been told D2L is working on it.
At this time I don't have an ETA to share, though should that change we'll notify the community through this channel.
I realize this isn't the update you were hoping for.
I've asked the team and unfortunately there is no new update on SSO yet.
We are currently prioritizing the possibility to have multiple admins, resend/revoke users and additional functionality for the classes on the D2L portal.
This update is scheduled to be launched in the June time-frame.
It has been awhile so I figured I would touch base to see if any progress has been made regarding an API or SSO integration. We have ~18k students but less than 3% of them need access so we can't bulk load with a CSV.