Basically what the title says. We have our Portal setup to use our organization's Enterprise logins via SAML. Our users love this, as it is completely seamless to them!
However, a problem that we've ran into is that 3rd party systems integrating with our GIS (in our case Tyler EnerGov, and possibly one more we're working on configuring now) have declared that they don't support Portal integration via SAML, and don't plan to. The best workaround to this would be to be the ability to link a built-in/ArcGIS portal account to an enterprise login. This would be similar in behavior to how you can sign into various web applications with your Google/Facebook/etc. account; the user's actual account would be controlled by the Portal, but the enterprise login would just be another way of accessing it.
Is this something we can currently do, or is it something on the Road Map? I haven't been able to find any documentation on how to do it, and the current behavior seems to be that you can either login to your account via enterprise OR built-in login (but not both for the same account); i.e. I can't login to my portal account if it is associated with an account from our enterprise.
(But not this)
Currently, built-in accounts are separate from Enterprise/SAML accounts. There are no currently plans to merge the two, as Enterprise accounts are derived from and managed by Active Directory, whereas built-in accounts have no such association.
Perhaps your third-party system supports Enterprise logins in some other way than SAML? So long as the NameID (username) remains the same, content should still be associated with the Enterprise account in Portal.