Which authentication method overrides any other previously configured user authentication on FortiSASE?

Comprehensive and Detailed Explanation From FortiSASE 24.x/25.x, FortiOS 7.4, FortiAuthenticator 6.5, FortiClient 7.0 and later Exact Extract study guide:

In FortiSASE environments, Single Sign-On (SSO) is prioritized as the primary enterprise authentication mechanism. According to the FortiSASE Configuration Guide and Security Operations documentation, when you configure SAML SSO (Single Sign-On), it serves as a global authentication setting that overrides any previously configured local or remote (RADIUS/LDAP) user authentication methods for the secure web gateway (SWG) and VPN tunnels.

The architectural logic is designed to ensure a seamless "Zero Trust" identity provider (IdP) experience. Once SSO is enabled and configured (typically using Azure AD, Okta, or FortiAuthenticator as the IdP), FortiSASE redirects authentication requests to the defined IdP. This effectively supersedes manual local user databases or legacy RADIUS configurations to maintain a single source of truth for identity management. While MFA is often a component of the authentication process, it is a secondary factor, whereas SSO is the foundational method that dictates the authentication flow and overrides prior settings.