Using c# and attempting to use WMI InvokeMethod SetBIOSAttributes only returns "Invalid method Parameter(s)"

I am not unknown to WMI, but the DCIM_BIOSService class got me really scratching my head... First attempts with ManagementObject style only rendered: {"Invalid method Parameter(s) "}.
Couldn't figure out what my problem was... so I changed to Cim style code. Below is an attempt to change Microphone from enabled to disabled state without setting or have a admin password set. But, it doesn't work:
               
  string computer = "localhost";
                CimSession Session = CimSession.Create(computer);
             
                UInt32[] BiosServiceResult = { 0 };
               
                Microsoft.Management.Infrastructure.Options.CimOperationOptions cooBiosElement = new Microsoft.Management.Infrastructure.Options.CimOperationOptions();
               
                IEnumerable ciBiosElementInstances = Session.QueryInstances("root\\dcim\\sysman", "WQL", "select * from CIM_BIOSElement", cooBiosElement);
                CimInstance ciBiosElementInstance = ciBiosElementInstances.FirstOrDefault();
               
                CimInstance ciBiosServiceInstance = new CimInstance("DCIM_BIOSService", "root\\dcim\\sysman");
                CimMethodParametersCollection cmpcBiosService = new CimMethodParametersCollection();
                cmpcBiosService.Add( CimMethodParameter.Create("AttributeName", new string[] { "Microphone" }, Microsoft.Management.Infrastructure.CimType.StringArray, CimFlags.In));
                cmpcBiosService.Add(CimMethodParameter.Create("AttributeValue", new string[] { "1" }, Microsoft.Management.Infrastructure.CimType.StringArray, CimFlags.In));
                cmpcBiosService.Add(CimMethodParameter.Create("TargetBIOS", ciBiosElementInstance, Microsoft.Management.Infrastructure.CimType.Reference, CimFlags.In));
                cmpcBiosService.Add(CimMethodParameter.Create("AuthorizationToken", null, Microsoft.Management.Infrastructure.CimType.Instance, CimFlags.In));
                //cmpcBiosService.Add(CimMethodParameter.Create("PasswordEncoding", (UInt32) 2  , Microsoft.Management.Infrastructure.CimType.UInt32, CimFlags.In));
                //cmpcBiosService.Add(CimMethodParameter.Create("SetResult", BiosServiceResult, Microsoft.Management.Infrastructure.CimType.UInt32Array, CimFlags.Out));
               
               CimMethodResult cmrBIOSService = Session.InvokeMethod(ciBiosServiceInstance, "SetBIOSAttributes", cmpcBiosService);

Now, going through the DCIM_Server_BIOSService.mof file and examining the SetBIOSAttributes method, I notice:

"When required, a token to modify BIOSAttribute "
             "values for this computer system. This is usually "
             "the BIOS administrator password. If this is a "
             "password, the PasswordEncoding parameter shall be "
             "used to denote the format of the password string. "
             "For example: the CIM_SharedCredential subclass may "
             "be utilized. In that case, the "
             "CIM_SharedCredential.Secret might be required and "
             "if is not specified this method would return 6 "
             "Invalid Parameter."

Now, I am merely attempting to alter simple settings, like Microphone or Wake-On-LAN, for which no BIOS admin password is required - imho. But, it all fails.
Anyone got some tips on how to get this method working in c# code?! So, no powershell escapes, as shown in another thread as a work around:

var tpm = @"(gwmi DCIM_BIOSService -namespace root\dcim\sysman -cn " + serial + ").SetBIOSAttributes($null,$null,'Trusted Platform Module','1', $null)";
                                var shell = PowerShell.Create();
                                shell.Commands.AddScript(tpm.ToString());
                                var results = shell.Invoke();

en.community.dell.com/.../19592437