Configuring DEP Profiles for IdP Authentication

What
Configuring Apple Devices DEP Profiles to use IdP authentication.
When/Why
We'll need to configure each DEP profile with which we would like to use IdP authentication (but it is simple to do) 
How
You'll simply notice there is a new checkbox in the DEP profile for "Custom Enrollment".  If that checkbox is checked in a profile, IdP enrollment will be used (if configured of course):
Once configured, you'll notice your devices will begin prompting for IdP authentication at enrollment time.
Known Issue
With Okta integration for macOS ADE enrollment there is a known issue with the initial load of the login window.  You will see that window appear with what looks like a bad page load, which is basically correct.  If you right-click, reload this page, it will load correctly.  (See below). Note that this issue will be resolved in an upcoming revision.
Related Content
IdP Setup: Google
IdP Setup: Azure AD
IdP Setup: Okta
Admin Login in Using an IdP Provider