I've created a custom STS and have setup trust with SharePoint via New-SPTrustedIdentityTokenIssuer. I can use Central Admin to configure a Web Application to use both NTLM and the STS, however I can't do that via PowerShell.
Is there a PowerShell command to do that? Set-SPWebApplication has the AuthenticationMethod and AuthenticationProvider parameters, but if I specify both, only AuthenticationProvider is applied, i.e. Windows Authentication is unticked.
Any help greatly appreciated!