Update Custom Login via Management API

Update. The Patch Client API (/api/v2/clients/{id}) has the following fields in it…

{
  "custom_login_page_on": true,
  "custom_login_page": "<div/>",
  "custom_login_page_preview": "<div/>"
}

This will update the login page for a client (application). This does NOT update the Universal Login page for my tenant. At this point, turning on Universal Login for my tenant does NOT override the custom_login_page I set for a client. There is also no way to know through the Dashboard if a custom login page is set for a client. So the question still stands…

  1. Is there a way to update the Universal Login page through the management API?
  2. Is the custom_login_page feature of the client API a deprecated feature?