Implementing SSO is a nightmare, particularly if customers want controls on their side. My view is that you should use Cognito (simple) or Auth0 (simple but ex

Implementing SSO is a nightmare, particularly if customers want controls on their side. My view is that you should use Cognito (simple) or Auth0 (simple but expensive) and build a self-setup page for it. Then if customers want it, it's on them to deal with configuring. Oh, and push them all to OpenID because it's a lot less hassle than SAML. If you're selling to big businesses (and you generally want to be), they'll pay for it anyway because this sort of security thing falls under various box ticking exercises for ISO certifications.