Recommend using custom SiPolicy.xml

[soleera]

As of at least Windows 11 23H2, it's possible to install the ConfigCI powershell module without needing Education/Enterprise editions:
gci $Env:SystemRoot\servicing\Packages\*ConfigCI*.mum | % { dism /online /norestart /add-package:"$_" }
This makes it much easier to customize and recompile SiPolicy.xml, which is preferable to the currently reccomended method of using the generic policy binary.
There's also a GUI interface called WDAC wizard to help make the policy editing process a little easier; generating the base policy this way also means you don't need to worry about scanning any system folders either.

As an example, this is what my current working SiPolicy.xml looks like:

<?xml version="1.0" encoding="utf-8"?>
<SiPolicy xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="urn:schemas-microsoft-com:sipolicy">
  <VersionEx>10.2.2.1</VersionEx>
  <PolicyTypeID>{A244370E-44C9-4C06-B551-F6016E563076}</PolicyTypeID>
  <PlatformID>{2E07F7E4-194C-4D20-B7C9-6F44A6C5A234}</PlatformID>
  <Rules>
    <Rule>
      <Option>Enabled:Unsigned System Integrity Policy</Option>
    </Rule>
    <Rule>
      <Option>Enabled:Advanced Boot Options Menu</Option>
    </Rule>
    <Rule>
      <Option>Enabled:Inherit Default Policy</Option>
    </Rule>
    <Rule>
      <Option>Enabled:Update Policy No Reboot</Option>
    </Rule>
  </Rules>
  <EKUs>
    <EKU ID="ID_EKU_WINDOWS" Value="010A2B0601040182370A0306" FriendlyName="" />
    <EKU ID="ID_EKU_ELAM" Value="010A2B0601040182373D0401" FriendlyName="" />
    <EKU ID="ID_EKU_HAL_EXT" Value="010A2B0601040182373D0501" FriendlyName="" />
    <EKU ID="ID_EKU_WHQL" Value="010A2B0601040182370A0305" FriendlyName="" />
  </EKUs>
  <FileRules />
  <Signers>
    <Signer Name="Microsoft Product Root 2010 Windows EKU" ID="ID_SIGNER_WINDOWS_PRODUCTION_0">
      <CertRoot Type="Wellknown" Value="06" />
      <CertEKU ID="ID_EKU_WINDOWS" />
    </Signer>
    <Signer Name="Microsoft Product Root 2010 ELAM EKU" ID="ID_SIGNER_ELAM_PRODUCTION_1">
      <CertRoot Type="Wellknown" Value="06" />
      <CertEKU ID="ID_EKU_ELAM" />
    </Signer>
    <Signer Name="Microsoft Product Root 2010 HAL EKU" ID="ID_SIGNER_HAL_PRODUCTION_2">
      <CertRoot Type="Wellknown" Value="06" />
      <CertEKU ID="ID_EKU_HAL_EXT" />
    </Signer>
    <Signer Name="Microsoft Product Root 2010 WHQL EKU" ID="ID_SIGNER_WHQL_SHA2_3">
      <CertRoot Type="Wellknown" Value="06" />
      <CertEKU ID="ID_EKU_WHQL" />
    </Signer>
    <Signer Name="Microsoft Product Root WHQL EKU SHA1" ID="ID_SIGNER_WHQL_SHA1_4">
      <CertRoot Type="Wellknown" Value="05" />
      <CertEKU ID="ID_EKU_WHQL" />
    </Signer>
    <Signer Name="Microsoft Product Root WHQL EKU MD5" ID="ID_SIGNER_WHQL_MD5_5">
      <CertRoot Type="Wellknown" Value="04" />
      <CertEKU ID="ID_EKU_WHQL" />
    </Signer>
    <Signer Name="MincryptKnownRootMicrosoftCodeVerificationRoot2006" ID="ID_SIGNER_MICROSOFT_CODEVERIFICATION_2006_0_0">
      <CertRoot Type="Wellknown" Value="08" />
    </Signer>
    <Signer Name="Localhost Kernel Mode Driver Certificate" ID="ID_SIGNER_LOCALHOST_0">
      <CertRoot Type="TBS" Value="XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" />
      <CertPublisher Value="Localhost Kernel Mode Driver Certificate" />
    </Signer>
  </Signers>
  <SigningScenarios>
    <SigningScenario ID="ID_SIGNINGSCENARIO_DRIVERS_1" FriendlyName="Auto generated policy on 02-06-2024" Value="131">
      <ProductSigners>
        <AllowedSigners>
          <AllowedSigner SignerId="ID_SIGNER_WINDOWS_PRODUCTION_0" />
          <AllowedSigner SignerId="ID_SIGNER_ELAM_PRODUCTION_1" />
          <AllowedSigner SignerId="ID_SIGNER_HAL_PRODUCTION_2" />
          <AllowedSigner SignerId="ID_SIGNER_WHQL_SHA2_3" />
          <AllowedSigner SignerId="ID_SIGNER_WHQL_SHA1_4" />
          <AllowedSigner SignerId="ID_SIGNER_WHQL_MD5_5" />
          <AllowedSigner SignerId="ID_SIGNER_MICROSOFT_CODEVERIFICATION_2006_0_0" />
          <AllowedSigner SignerId="ID_SIGNER_LOCALHOST_0" />
        </AllowedSigners>
      </ProductSigners>
    </SigningScenario>
  </SigningScenarios>
  <UpdatePolicySigners />
  <CiSigners />
  <HvciOptions>0</HvciOptions>
  <Settings />
</SiPolicy>