diff --git a/src/libraries/Microsoft.Extensions.HostFactoryResolver/src/Microsoft.Extensions.HostFactoryResolver.Sources.csproj b/src/libraries/Microsoft.Extensions.HostFactoryResolver/src/Microsoft.Extensions.HostFactoryResolver.Sources.csproj
index dff90383f96cbf..31cd86025ee019 100644
--- a/src/libraries/Microsoft.Extensions.HostFactoryResolver/src/Microsoft.Extensions.HostFactoryResolver.Sources.csproj
+++ b/src/libraries/Microsoft.Extensions.HostFactoryResolver/src/Microsoft.Extensions.HostFactoryResolver.Sources.csproj
@@ -3,8 +3,6 @@
        package infra globs for .cs files. -->
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
-    <!-- The project doesn't compile anything therefore create the package during build. -->
-    <GeneratePackageOnBuild Condition="'$(BuildingAnOfficialBuildLeg)' != 'true'">true</GeneratePackageOnBuild>
     <IsShipping>false</IsShipping>
     <SuppressDependenciesWhenPacking>true</SuppressDependenciesWhenPacking>
     <!-- This is a source package which includes all .cs files by default. -->
diff --git a/src/libraries/Microsoft.NETCore.Platforms/src/Microsoft.NETCore.Platforms.csproj b/src/libraries/Microsoft.NETCore.Platforms/src/Microsoft.NETCore.Platforms.csproj
index 299a8b2ceb7342..9aad9681e31f98 100644
--- a/src/libraries/Microsoft.NETCore.Platforms/src/Microsoft.NETCore.Platforms.csproj
+++ b/src/libraries/Microsoft.NETCore.Platforms/src/Microsoft.NETCore.Platforms.csproj
@@ -6,8 +6,6 @@
     <PackageId>$(MSBuildProjectName)</PackageId>
     <AvoidRestoreCycleOnSelfReference>true</AvoidRestoreCycleOnSelfReference>
     <AssemblyName>Microsoft.NETCore.Platforms.BuildTasks</AssemblyName>
-    <!-- The only output of this project is the package as the tasks aren't packaged. -->
-    <GeneratePackageOnBuild Condition="'$(BuildingAnOfficialBuildLeg)' != 'true'">true</GeneratePackageOnBuild>
 
     <IsSourceProject>false</IsSourceProject>
     <IsPackable>true</IsPackable>
diff --git a/src/libraries/Microsoft.Windows.Compatibility/src/Microsoft.Windows.Compatibility.csproj b/src/libraries/Microsoft.Windows.Compatibility/src/Microsoft.Windows.Compatibility.csproj
new file mode 100644
index 00000000000000..86afb922f869e5
--- /dev/null
+++ b/src/libraries/Microsoft.Windows.Compatibility/src/Microsoft.Windows.Compatibility.csproj
@@ -0,0 +1,70 @@
+<Project Sdk="Microsoft.Build.NoTargets">
+  <PropertyGroup>
+    <!-- Using a csproj extension to get the correct multi-targeting behavior. -->
+    <TargetFrameworks>$(NetCoreAppCurrent);netcoreapp3.1;netstandard2.1;netstandard2.0</TargetFrameworks>
+    <IsPackable>true</IsPackable>
+    <!-- Reference the outputs for the dependency nodes calculation. -->
+    <NoTargetsDoNotReferenceOutputAssemblies>false</NoTargetsDoNotReferenceOutputAssemblies>
+    <!-- This is a meta package and doesn't contain any libs. -->
+    <NoWarn>$(NoWarn);NU5128</NoWarn>
+    <PackageDescription>This Windows Compatibility Pack provides access to APIs that were previously available only for .NET Framework. It can be used from both .NET Core as well as .NET Standard.</PackageDescription>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="$(LibrariesProjectRoot)Microsoft.Win32.Registry.AccessControl\src\Microsoft.Win32.Registry.AccessControl.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)Microsoft.Win32.SystemEvents\src\Microsoft.Win32.SystemEvents.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.CodeDom\src\System.CodeDom.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.ComponentModel.Composition\src\System.ComponentModel.Composition.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Configuration.ConfigurationManager\src\System.Configuration.ConfigurationManager.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Data.Odbc\src\System.Data.Odbc.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Data.OleDb\src\System.Data.OleDb.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Diagnostics.EventLog\src\System.Diagnostics.EventLog.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Diagnostics.PerformanceCounter\src\System.Diagnostics.PerformanceCounter.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.DirectoryServices.AccountManagement\src\System.DirectoryServices.AccountManagement.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.DirectoryServices.Protocols\src\System.DirectoryServices.Protocols.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.DirectoryServices\src\System.DirectoryServices.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Drawing.Common\src\System.Drawing.Common.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.IO.Packaging\src\System.IO.Packaging.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.IO.Ports\src\System.IO.Ports.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Management\src\System.Management.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Reflection.Context\src\System.Reflection.Context.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Runtime.Caching\src\System.Runtime.Caching.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Security.Cryptography.Pkcs\src\System.Security.Cryptography.Pkcs.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Security.Cryptography.ProtectedData\src\System.Security.Cryptography.ProtectedData.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Security.Cryptography.Xml\src\System.Security.Cryptography.Xml.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Security.Permissions\src\System.Security.Permissions.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.ServiceModel.Syndication\src\System.ServiceModel.Syndication.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.ServiceProcess.ServiceController\src\System.ServiceProcess.ServiceController.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Speech\src\System.Speech.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Text.Encoding.CodePages\src\System.Text.Encoding.CodePages.csproj" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Threading.AccessControl\src\System.Threading.AccessControl.csproj" />
+  </ItemGroup>
+
+  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'netstandard2.1'))">
+    <ProjectReference Include="$(LibrariesProjectRoot)System.ComponentModel.Composition.Registration\src\System.ComponentModel.Composition.Registration.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="System.Data.SqlClient" Version="$(SystemDataSqlClientVersion)" />  
+    <PackageReference Include="System.ServiceModel.Primitives;
+                                     System.ServiceModel.Duplex;
+                                     System.ServiceModel.Http;
+                                     System.ServiceModel.NetTcp;
+                                     System.ServiceModel.Security"
+                      Version="$(ServiceModelVersion)" />
+  </ItemGroup>
+
+  <!-- Packages which are inbox in NET6 and shouldn't and can't be referenced anymore. -->
+  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net6.0'))">
+    <PackageReference Include="Microsoft.Win32.Registry" Version="$(MicrosoftWin32RegistryVersion)" />
+    <PackageReference Include="System.Data.DataSetExtensions" Version="$(SystemDataDataSetExtensionsVersion)" />
+    <PackageReference Include="System.IO.FileSystem.AccessControl" Version="$(SystemIOFileSystemAccessControlVersion)" />
+    <PackageReference Include="System.IO.Pipes.AccessControl" Version="$(SystemIOPipesAccessControlVersion)" />
+    <PackageReference Include="System.Reflection.Emit" Version="$(SystemReflectionEmitVersion)" />
+    <PackageReference Include="System.Reflection.Emit.ILGeneration" Version="$(SystemReflectionEmitILGenerationVersion)" />
+    <PackageReference Include="System.Reflection.Emit.Lightweight" Version="$(SystemReflectionEmitLightweightVersion)" />
+    <PackageReference Include="System.Security.AccessControl" Version="$(SystemSecurityAccessControlVersion)" />
+    <PackageReference Include="System.Security.Cryptography.Cng" Version="$(SystemSecurityCryptographyCngVersion)" />
+    <PackageReference Include="System.Security.Principal.Windows" Version="$(SystemSecurityPrincipalWindowsVersion)" />
+  </ItemGroup>
+</Project>
diff --git a/src/libraries/libraries-packages.proj b/src/libraries/libraries-packages.proj
index f67803e79972bc..0bc55ebbffd53b 100644
--- a/src/libraries/libraries-packages.proj
+++ b/src/libraries/libraries-packages.proj
@@ -2,13 +2,13 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.DotNet.Build.Tasks.Packaging" Version="$(MicrosoftDotNetBuildTasksPackagingVersion)" />
+  </ItemGroup>
 
-    <ProjectReference Include="$(MSBuildThisFileDirectory)System.Runtime.Experimental\ref\System.Runtime.Experimental.csproj"
-                      Condition="'$(BuildAllConfigurations)' == 'true'" />
+  <ItemGroup Condition="'$(BuildAllConfigurations)' == 'true'">
+    <ProjectReference Include="$(MSBuildThisFileDirectory)System.Runtime.Experimental\ref\System.Runtime.Experimental.csproj" />
     <ProjectReference Include="$(PkgDir)*\*.proj" Exclude="$(PkgDir)test\*" />
     <ProjectReference Include="$(MSBuildThisFileDirectory)*\src\*.*proj"
-                      Condition="'$(BuildAllConfigurations)' == 'true'"
-                      Exclude="$(MSBuildThisFileDirectory)*\src\**\*.shproj"/>
+                      Exclude="$(MSBuildThisFileDirectory)*\src\**\*.shproj" />
   </ItemGroup>
 
   <!-- Need the PackageIndexFile file property from baseline.props -->
diff --git a/src/libraries/pkg/Microsoft.Windows.Compatibility/Microsoft.Windows.Compatibility.pkgproj b/src/libraries/pkg/Microsoft.Windows.Compatibility/Microsoft.Windows.Compatibility.pkgproj
deleted file mode 100644
index c1a3f16e19ec1c..00000000000000
--- a/src/libraries/pkg/Microsoft.Windows.Compatibility/Microsoft.Windows.Compatibility.pkgproj
+++ /dev/null
@@ -1,98 +0,0 @@
-<Project DefaultTargets="Build">
-  <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props))" />
-  <PropertyGroup>
-    <!-- We don't need to harvest the stable packages to build this -->
-    <HarvestStablePackage>false</HarvestStablePackage>
-    <PackageDescription>This Windows Compatibility Pack provides access to APIs that were previously available only for .NET Framework. It can be used from both .NET Core as well as .NET Standard.</PackageDescription>
-  </PropertyGroup>
-  <ItemDefinitionGroup>
-    <PrereleaseLibraryPackage>
-      <Version>$(PackageVersion)</Version>
-    </PrereleaseLibraryPackage>
-    <NS21PrereleaseLibraryPackage>
-      <Version>$(PackageVersion)</Version>
-    </NS21PrereleaseLibraryPackage>
-  </ItemDefinitionGroup>
-  <ItemGroup>
-    <PrereleaseLibraryPackage Include="Microsoft.Win32.Registry.AccessControl" />
-    <PrereleaseLibraryPackage Include="Microsoft.Win32.SystemEvents" />
-    <PrereleaseLibraryPackage Include="System.CodeDom" />
-    <PrereleaseLibraryPackage Include="System.ComponentModel.Composition" />
-    <PrereleaseLibraryPackage Include="System.Configuration.ConfigurationManager" />
-    <PrereleaseLibraryPackage Include="System.Data.Odbc" />
-    <PrereleaseLibraryPackage Include="System.Data.OleDb" />
-    <PrereleaseLibraryPackage Include="System.Drawing.Common" />
-    <PrereleaseLibraryPackage Include="System.Diagnostics.EventLog" />
-    <PrereleaseLibraryPackage Include="System.Diagnostics.PerformanceCounter" />
-    <PrereleaseLibraryPackage Include="System.DirectoryServices" />
-    <PrereleaseLibraryPackage Include="System.DirectoryServices.AccountManagement" />
-    <PrereleaseLibraryPackage Include="System.DirectoryServices.Protocols" />
-    <PrereleaseLibraryPackage Include="System.IO.Packaging" />
-    <PrereleaseLibraryPackage Include="System.IO.Ports" />
-    <PrereleaseLibraryPackage Include="System.Management" />
-    <PrereleaseLibraryPackage Include="System.Runtime.Caching" />
-    <PrereleaseLibraryPackage Include="System.Security.Cryptography.Pkcs" />
-    <PrereleaseLibraryPackage Include="System.Security.Cryptography.ProtectedData" />
-    <PrereleaseLibraryPackage Include="System.Security.Cryptography.Xml" />
-    <PrereleaseLibraryPackage Include="System.Security.Permissions" />
-    <PrereleaseLibraryPackage Include="System.ServiceModel.Syndication" />
-    <PrereleaseLibraryPackage Include="System.ServiceProcess.ServiceController" />
-    <PrereleaseLibraryPackage Include="System.Speech" />
-    <PrereleaseLibraryPackage Include="System.Text.Encoding.CodePages" />
-    <PrereleaseLibraryPackage Include="System.Threading.AccessControl" />
-
-    <NS21PrereleaseLibraryPackage Include="System.ComponentModel.Composition.Registration" />
-    <NS21PrereleaseLibraryPackage Include="System.Reflection.Context" />
-
-    <!-- Packages which are inbox in NET6 and don't need to be referenced. -->
-    <BeforeNET6LibraryPackage Include="Microsoft.Win32.Registry" Version="$(MicrosoftWin32RegistryVersion)" />
-    <BeforeNET6LibraryPackage Include="System.Data.DataSetExtensions" Version="$(SystemDataDataSetExtensionsVersion)" />
-    <BeforeNET6LibraryPackage Include="System.IO.FileSystem.AccessControl" Version="$(SystemIOFileSystemAccessControlVersion)" />
-    <BeforeNET6LibraryPackage Include="System.IO.Pipes.AccessControl" Version="$(SystemIOPipesAccessControlVersion)" />
-    <BeforeNET6LibraryPackage Include="System.Reflection.Emit" Version="$(SystemReflectionEmitVersion)" />
-    <BeforeNET6LibraryPackage Include="System.Reflection.Emit.ILGeneration" Version="$(SystemReflectionEmitILGenerationVersion)" />
-    <BeforeNET6LibraryPackage Include="System.Reflection.Emit.Lightweight" Version="$(SystemReflectionEmitLightweightVersion)" />
-    <BeforeNET6LibraryPackage Include="System.Security.AccessControl" Version="$(SystemSecurityAccessControlVersion)" />
-    <BeforeNET6LibraryPackage Include="System.Security.Cryptography.Cng" Version="$(SystemSecurityCryptographyCngVersion)" />
-    <BeforeNET6LibraryPackage Include="System.Security.Principal.Windows" Version="$(SystemSecurityPrincipalWindowsVersion)" />
-
-    <!-- External packages -->
-    <ExternalLibraryPackage Include="System.Data.SqlClient" Version="$(SystemDataSqlClientVersion)" />  
-    <ExternalLibraryPackage Include="System.ServiceModel.Primitives;
-                                     System.ServiceModel.Duplex;
-                                     System.ServiceModel.Http;
-                                     System.ServiceModel.NetTcp;
-                                     System.ServiceModel.Security"
-                            Version="$(ServiceModelVersion)" />
-  </ItemGroup>
-
-  <ItemGroup>
-    <IndexedDependency Include="@(PrereleaseLibraryPackage);
-                                @(NS21PrereleaseLibraryPackage)"
-                       TargetFramework="net6.0" />
-    <IndexedDependency Include="@(BeforeNET6LibraryPackage);
-                                @(PrereleaseLibraryPackage);
-                                @(NS21PrereleaseLibraryPackage)"
-                       TargetFramework="netcoreapp3.1" />
-    <IndexedDependency Include="@(BeforeNET6LibraryPackage);
-                                @(PrereleaseLibraryPackage);
-                                @(NS21PrereleaseLibraryPackage)"
-                       TargetFramework="netstandard2.1" />
-    <IndexedDependency Include="@(BeforeNET6LibraryPackage);
-                                @(PrereleaseLibraryPackage)"
-                       TargetFramework="netstandard2.0" />
-  </ItemGroup>
-
-  <ItemGroup>
-    <Dependency Include="@(ExternalLibraryPackage)"
-                TargetFramework="net6.0" />
-    <Dependency Include="@(ExternalLibraryPackage)"
-                TargetFramework="netcoreapp3.1" />
-    <Dependency Include="@(ExternalLibraryPackage)"
-                TargetFramework="netstandard2.0" />
-    <Dependency Include="@(ExternalLibraryPackage)"
-                TargetFramework="netstandard2.1" />
-  </ItemGroup>
-
-  <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.targets))" />
-</Project>
diff --git a/src/libraries/pkg/Microsoft.Windows.Compatibility/Microsoft.Windows.Compatibility.proj b/src/libraries/pkg/Microsoft.Windows.Compatibility/Microsoft.Windows.Compatibility.proj
deleted file mode 100644
index 17a7f16890297a..00000000000000
--- a/src/libraries/pkg/Microsoft.Windows.Compatibility/Microsoft.Windows.Compatibility.proj
+++ /dev/null
@@ -1,10 +0,0 @@
-<Project DefaultTargets="Build">
-  <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props))" />
-
-  <!-- only build during the AllConfigurations leg because it depends on other nupkgs from this leg -->
-  <ItemGroup Condition="'$(BuildAllConfigurations)' == 'true'">
-    <Project Include="$(MSBuildProjectName).pkgproj" />
-  </ItemGroup>
-
-  <Import Project="$([MSBuild]::GetPathOfFileAbove(dir.traversal.targets))" />
-</Project>
\ No newline at end of file
diff --git a/src/libraries/pkg/baseline/packageIndex.json b/src/libraries/pkg/baseline/packageIndex.json
index 6c24d93bbb4860..09f1be0796e397 100644
--- a/src/libraries/pkg/baseline/packageIndex.json
+++ b/src/libraries/pkg/baseline/packageIndex.json
@@ -1439,25 +1439,6 @@
         "6.0.0.0": "6.0.0"
       }
     },
-    "Microsoft.Windows.Compatibility": {
-      "StableVersions": [
-        "2.0.0",
-        "2.0.1",
-        "2.1.0",
-        "2.1.1",
-        "3.0.0",
-        "3.0.1",
-        "5.0.0"
-      ],
-      "InboxOn": {}
-    },
-    "Microsoft.Windows.Compatibility.Shims": {
-      "StableVersions": [
-        "2.0.0",
-        "2.0.1"
-      ],
-      "InboxOn": {}
-    },
     "Microsoft.XmlSerializer.Generator": {
       "StableVersions": [
         "1.0.0",
diff --git a/src/libraries/pkg/runtime.native.System.IO.Ports/runtime.native.System.IO.Ports.proj b/src/libraries/pkg/runtime.native.System.IO.Ports/runtime.native.System.IO.Ports.proj
index a1ec1ea4bd1c98..4cccee8eede3c0 100644
--- a/src/libraries/pkg/runtime.native.System.IO.Ports/runtime.native.System.IO.Ports.proj
+++ b/src/libraries/pkg/runtime.native.System.IO.Ports/runtime.native.System.IO.Ports.proj
@@ -1,7 +1,7 @@
 <Project DefaultTargets="Build">
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props))" />
 
-  <ItemGroup Condition="'$(BuildAllConfigurations)' == 'true'">
+  <ItemGroup>
     <!-- identity project built in AllConfigurations leg, runtime specific projects are included through netcoreapp.rids.props -->
     <Project Include="$(MSBuildProjectName).pkgproj" />
   </ItemGroup>
diff --git a/src/libraries/src.proj b/src/libraries/src.proj
index 5862082f7e3ef9..0faa26075e2d7d 100644
--- a/src/libraries/src.proj
+++ b/src/libraries/src.proj
@@ -7,6 +7,12 @@
   <ItemGroup>
     <_allSrc Include="$(MSBuildThisFileDirectory)*\src\*.csproj"
              Exclude="@(ProjectExclusions)" />
+    <!-- Don't build ProjectReferences of the compat pack in a traversal build to avoid unnecessary incremental builds. -->
+    <_allSrc Update="$(MSBuildThisFileDirectory)Microsoft.Windows.Compatibility\src\Microsoft.Windows.Compatibility.csproj"
+             AdditionalProperties="BuildProjectReferences=false" />
+    <!-- Only build the compat pack in the allconfigurations leg. -->
+    <_allSrc Remove="$(MSBuildThisFileDirectory)Microsoft.Windows.Compatibility\src\Microsoft.Windows.Compatibility.csproj"
+             Condition="'$(BuildAllConfigurations)' != 'true'" />
     <NonNetCoreAppProject Include="@(_allSrc)"
                           Exclude="@(NetCoreAppLibrary->'%(Identity)\src\%(Identity).csproj')" />
     <NetCoreAppProject Include="$(CoreLibProject);