Hello @Kevin Taber ,
Enterprise applications in Azure AD cannot have more than one RelayState because this value is static and this instructs the application where to redirect users after authentication is completed, and the value is typically a URL or URL path as shown below that takes users to a specific location within the application. The value in this form only takes effect in an IdP-initiated SSO flow.
To support multiple/Dynamic RelayState URLs, your app must use SP-initiated SSO, and send the RelayState as a parameter in the SAML request as shown below, so that Azure AD can return the same information in the SAML Response.
You can get more details about Relaystate from SAML V2.0 technical description. Hope this helps.
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