diff --git a/src/tests/JIT/BBT/Scenario4/Not-Int32.ilproj b/src/tests/JIT/BBT/Scenario4/Not-Int32.ilproj
index e04e4cec9bd7b4..52a4688829ccc0 100644
--- a/src/tests/JIT/BBT/Scenario4/Not-Int32.ilproj
+++ b/src/tests/JIT/BBT/Scenario4/Not-Int32.ilproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.IL">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <CLRTestPriority>1</CLRTestPriority>
   </PropertyGroup>
   <PropertyGroup>
diff --git a/src/tests/JIT/CodeGenBringUpTests/Directory.Build.props b/src/tests/JIT/CodeGenBringUpTests/Directory.Build.props
index 689ebf8db31e1a..8f1448d9f2db2d 100644
--- a/src/tests/JIT/CodeGenBringUpTests/Directory.Build.props
+++ b/src/tests/JIT/CodeGenBringUpTests/Directory.Build.props
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
-  <Import Project="..\..\Directory.Merged.props" />
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props, $(MSBuildThisFileDirectory)..))" />
 
   <PropertyGroup>
diff --git a/src/tests/JIT/Directed/Directory.Build.props b/src/tests/JIT/Directed/Directory.Build.props
index 608affd337da09..3b266bde56a6f0 100644
--- a/src/tests/JIT/Directed/Directory.Build.props
+++ b/src/tests/JIT/Directed/Directory.Build.props
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\Directory.Merged.props" />
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props, $(MSBuildThisFileDirectory)..))" />
 
   <PropertyGroup>
diff --git a/src/tests/JIT/Directory.Build.props b/src/tests/JIT/Directory.Build.props
index ed79eeaaadb984..997f32d0857909 100644
--- a/src/tests/JIT/Directory.Build.props
+++ b/src/tests/JIT/Directory.Build.props
@@ -1,4 +1,5 @@
 <Project>
+  <Import Project="..\Directory.Merged.props" />
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props, $(MSBuildThisFileDirectory)..))" />
 
   <PropertyGroup>
diff --git a/src/tests/JIT/Generics/Directory.Build.props b/src/tests/JIT/Generics/Directory.Build.props
index d500cf42b33e10..89a9ae31a3c81e 100644
--- a/src/tests/JIT/Generics/Directory.Build.props
+++ b/src/tests/JIT/Generics/Directory.Build.props
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
-  <Import Project="..\..\Directory.Merged.props" />
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props, $(MSBuildThisFileDirectory)..))" />
 
   <PropertyGroup>
diff --git a/src/tests/JIT/HardwareIntrinsics/Directory.Build.props b/src/tests/JIT/HardwareIntrinsics/Directory.Build.props
index 8df9869fb86991..5ae46d7b86415d 100644
--- a/src/tests/JIT/HardwareIntrinsics/Directory.Build.props
+++ b/src/tests/JIT/HardwareIntrinsics/Directory.Build.props
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
-  <Import Project="..\..\Directory.Merged.props" />
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props, $(MSBuildThisFileDirectory)..))" />
 
   <ItemGroup>
diff --git a/src/tests/JIT/IL_Conformance/Directory.Build.props b/src/tests/JIT/IL_Conformance/Directory.Build.props
index 4d1258218b4a07..396765fb5cd5c5 100644
--- a/src/tests/JIT/IL_Conformance/Directory.Build.props
+++ b/src/tests/JIT/IL_Conformance/Directory.Build.props
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\Directory.Merged.props" />
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props, $(MSBuildThisFileDirectory)..))" />
 
   <PropertyGroup>
diff --git a/src/tests/JIT/Intrinsics/BMI1Intrinsics.cs b/src/tests/JIT/Intrinsics/BMI1Intrinsics.cs
index ffb7f0cf73bb4b..43abe431cc40e5 100644
--- a/src/tests/JIT/Intrinsics/BMI1Intrinsics.cs
+++ b/src/tests/JIT/Intrinsics/BMI1Intrinsics.cs
@@ -1,13 +1,15 @@
 using System;
 using System.Runtime.CompilerServices;
+using Xunit;
 
 namespace BMI1Intrinsics
 {
-    internal class Program
+    public class Program
     {
         private static int _errorCode = 100;
 
-        static int Main()
+        [Fact]
+        public static int TestEntryPoint()
         {
             // bmi1 expression are folded to hwintrinsics that return identical results
 
diff --git a/src/tests/JIT/Intrinsics/BMI1Intrinsics_ro.csproj b/src/tests/JIT/Intrinsics/BMI1Intrinsics_ro.csproj
index eda151f5d9b96d..366a67c0974602 100644
--- a/src/tests/JIT/Intrinsics/BMI1Intrinsics_ro.csproj
+++ b/src/tests/JIT/Intrinsics/BMI1Intrinsics_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <DebugType>None</DebugType>
     <Optimize>True</Optimize>
   </PropertyGroup>
diff --git a/src/tests/JIT/Intrinsics/BMI1Intrinsicss_r.csproj b/src/tests/JIT/Intrinsics/BMI1Intrinsicss_r.csproj
index f7f4c3830b435e..d75b6c5854676b 100644
--- a/src/tests/JIT/Intrinsics/BMI1Intrinsicss_r.csproj
+++ b/src/tests/JIT/Intrinsics/BMI1Intrinsicss_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <DebugType>None</DebugType>
     <Optimize />
   </PropertyGroup>
diff --git a/src/tests/JIT/Intrinsics/BinaryPrimitivesReverseEndianness.cs b/src/tests/JIT/Intrinsics/BinaryPrimitivesReverseEndianness.cs
index 4fa6553ba130c9..527a2f3c2d27c4 100644
--- a/src/tests/JIT/Intrinsics/BinaryPrimitivesReverseEndianness.cs
+++ b/src/tests/JIT/Intrinsics/BinaryPrimitivesReverseEndianness.cs
@@ -7,10 +7,11 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using Internal;
+using Xunit;
 
 namespace BinaryPrimitivesReverseEndianness
 {
-    class Program
+    public class Program
     {
         public const int Pass = 100;
         public const int Fail = 0;
@@ -33,7 +34,8 @@ class Program
         private static readonly byte[] s_bufferLESigned64 = new byte[] { 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0x1e };
         private static readonly byte[] s_bufferBESigned64 = new byte[] { 0x1e, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10 };
 
-        static int Main()
+        [Fact]
+        public static int TestEntryPoint()
         {
             /*
              * CONST VALUE TESTS
diff --git a/src/tests/JIT/Intrinsics/BinaryPrimitivesReverseEndianness_r.csproj b/src/tests/JIT/Intrinsics/BinaryPrimitivesReverseEndianness_r.csproj
index cde2c06d9a6c2f..a83b751e3ea990 100644
--- a/src/tests/JIT/Intrinsics/BinaryPrimitivesReverseEndianness_r.csproj
+++ b/src/tests/JIT/Intrinsics/BinaryPrimitivesReverseEndianness_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/BinaryPrimitivesReverseEndianness_ro.csproj b/src/tests/JIT/Intrinsics/BinaryPrimitivesReverseEndianness_ro.csproj
index a0bee622bbd76d..44d587c9bc9eb5 100644
--- a/src/tests/JIT/Intrinsics/BinaryPrimitivesReverseEndianness_ro.csproj
+++ b/src/tests/JIT/Intrinsics/BinaryPrimitivesReverseEndianness_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/BitCast.il b/src/tests/JIT/Intrinsics/BitCast.il
index 0cba680ad3eff0..ce5d459d52cda2 100644
--- a/src/tests/JIT/Intrinsics/BitCast.il
+++ b/src/tests/JIT/Intrinsics/BitCast.il
@@ -5,6 +5,7 @@
 // This test checks implicit floating point and small type casts in IL
 
 .assembly extern System.Runtime {}
+.assembly extern xunit.core {}
 .assembly extern System.Console {}
 .assembly Bitcast {}
 
@@ -14,6 +15,9 @@
   .field private static int32 exitCode
   .method public hidebysig static int32  Main() cil managed
   {
+    .custom instance void [xunit.core]Xunit.FactAttribute::.ctor() = (
+        01 00 00 00
+    )
     .entrypoint
     // Code size       306 (0x132)
     .maxstack  3
diff --git a/src/tests/JIT/Intrinsics/BitCast.ilproj b/src/tests/JIT/Intrinsics/BitCast.ilproj
index 8b9c8251b5ca07..c0402c5a1314ad 100644
--- a/src/tests/JIT/Intrinsics/BitCast.ilproj
+++ b/src/tests/JIT/Intrinsics/BitCast.ilproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.IL">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <DebugType>PdbOnly</DebugType>
diff --git a/src/tests/JIT/Intrinsics/BitOperationsIntrinsics_r.csproj b/src/tests/JIT/Intrinsics/BitOperationsIntrinsics_r.csproj
index f89cfce21ad6bf..c260b9687474c3 100644
--- a/src/tests/JIT/Intrinsics/BitOperationsIntrinsics_r.csproj
+++ b/src/tests/JIT/Intrinsics/BitOperationsIntrinsics_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <DebugType>None</DebugType>
     <Optimize />
   </PropertyGroup>
diff --git a/src/tests/JIT/Intrinsics/BitOperationsIntrinsics_ro.csproj b/src/tests/JIT/Intrinsics/BitOperationsIntrinsics_ro.csproj
index 2f3601c1b1601f..a58eefb3d6c2a2 100644
--- a/src/tests/JIT/Intrinsics/BitOperationsIntrinsics_ro.csproj
+++ b/src/tests/JIT/Intrinsics/BitOperationsIntrinsics_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <DebugType>None</DebugType>
     <Optimize>True</Optimize>
   </PropertyGroup>
diff --git a/src/tests/JIT/Intrinsics/BitOperationsPopCount.cs b/src/tests/JIT/Intrinsics/BitOperationsPopCount.cs
index 1742b8f0428230..fe4c54970c3469 100644
--- a/src/tests/JIT/Intrinsics/BitOperationsPopCount.cs
+++ b/src/tests/JIT/Intrinsics/BitOperationsPopCount.cs
@@ -5,14 +5,16 @@
 using System;
 using System.Numerics;
 using System.Runtime.CompilerServices;
+using Xunit;
 
 namespace BitOperationsPopCountTest
 {
-    class Program
+    public class Program
     {
         private static int _errorCode = 100;
 
-        static int Main()
+        [Fact]
+        public static int TestEntryPoint()
         {
             // PopCount calls with a constant argument are folded
 
diff --git a/src/tests/JIT/Intrinsics/CreateSpan_il.il b/src/tests/JIT/Intrinsics/CreateSpan_il.il
index cd950298337bb8..2a8649714559fd 100644
--- a/src/tests/JIT/Intrinsics/CreateSpan_il.il
+++ b/src/tests/JIT/Intrinsics/CreateSpan_il.il
@@ -11,6 +11,7 @@
   .publickeytoken = (B0 3F 5F 7F 11 D5 0A 3A )                         // .?_....:
   .ver 7:0:0:0
 }
+.assembly extern xunit.core {}
 .assembly 'CreateSpan_il'
 {
   .custom instance void [System.Runtime]System.Runtime.CompilerServices.CompilationRelaxationsAttribute::.ctor(int32) = ( 01 00 08 00 00 00 00 00 ) 
@@ -37,12 +38,15 @@
 
 // =============== CLASS MEMBERS DECLARATION ===================
 
-.class private auto ansi beforefieldinit CreateSpanTest
+.class public auto ansi beforefieldinit CreateSpanTest
        extends [System.Runtime]System.Object
 {
-  .method private hidebysig static int32 
+  .method public hidebysig static int32 
           Main() cil managed
   {
+    .custom instance void [xunit.core]Xunit.FactAttribute::.ctor() = (
+        01 00 00 00
+    )
     .entrypoint
     // Code size       47 (0x2f)
     .maxstack  2
diff --git a/src/tests/JIT/Intrinsics/CreateSpan_il.ilproj b/src/tests/JIT/Intrinsics/CreateSpan_il.ilproj
index 403e74dc751563..73c3eaa050c418 100644
--- a/src/tests/JIT/Intrinsics/CreateSpan_il.ilproj
+++ b/src/tests/JIT/Intrinsics/CreateSpan_il.ilproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.IL">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <DebugType>PdbOnly</DebugType>
diff --git a/src/tests/JIT/Intrinsics/MathCeilingDouble.cs b/src/tests/JIT/Intrinsics/MathCeilingDouble.cs
index 78e6073d0e3a13..41578b67b23a44 100644
--- a/src/tests/JIT/Intrinsics/MathCeilingDouble.cs
+++ b/src/tests/JIT/Intrinsics/MathCeilingDouble.cs
@@ -3,10 +3,11 @@
 //
 
 using System;
+using Xunit;
 
 namespace MathCeilingDoubleTest
 {
-    class Program
+    public class Program
     {
         public const int Pass = 100;
         public const int Fail = 0;
@@ -31,7 +32,8 @@ class Program
             8.8
         };
 
-        unsafe static int Main()
+        [Fact]
+        public unsafe static int TestEntryPoint()
         {
             double localValue = 9.9;
 
diff --git a/src/tests/JIT/Intrinsics/MathCeilingDouble_r.csproj b/src/tests/JIT/Intrinsics/MathCeilingDouble_r.csproj
index 593c0683bd037c..c83772980697af 100644
--- a/src/tests/JIT/Intrinsics/MathCeilingDouble_r.csproj
+++ b/src/tests/JIT/Intrinsics/MathCeilingDouble_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathCeilingDouble_ro.csproj b/src/tests/JIT/Intrinsics/MathCeilingDouble_ro.csproj
index d84ffd21432832..680aa7c5399c82 100644
--- a/src/tests/JIT/Intrinsics/MathCeilingDouble_ro.csproj
+++ b/src/tests/JIT/Intrinsics/MathCeilingDouble_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathCeilingSingle.cs b/src/tests/JIT/Intrinsics/MathCeilingSingle.cs
index 3ce717316ee034..29d2c301525cf9 100644
--- a/src/tests/JIT/Intrinsics/MathCeilingSingle.cs
+++ b/src/tests/JIT/Intrinsics/MathCeilingSingle.cs
@@ -3,10 +3,11 @@
 //
 
 using System;
+using Xunit;
 
 namespace MathCeilingSingleTest
 {
-    class Program
+    public class Program
     {
         public const int Pass = 100;
         public const int Fail = 0;
@@ -31,7 +32,8 @@ class Program
             8.8f
         };
 
-        unsafe static int Main()
+        [Fact]
+        public unsafe static int TestEntryPoint()
         {
             float localValue = 9.9f;
 
diff --git a/src/tests/JIT/Intrinsics/MathCeilingSingle_r.csproj b/src/tests/JIT/Intrinsics/MathCeilingSingle_r.csproj
index 50cd39bcbc4bc9..61fed8486deafe 100644
--- a/src/tests/JIT/Intrinsics/MathCeilingSingle_r.csproj
+++ b/src/tests/JIT/Intrinsics/MathCeilingSingle_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathCeilingSingle_ro.csproj b/src/tests/JIT/Intrinsics/MathCeilingSingle_ro.csproj
index e2fa4cd179e96a..78e6f22f2ac452 100644
--- a/src/tests/JIT/Intrinsics/MathCeilingSingle_ro.csproj
+++ b/src/tests/JIT/Intrinsics/MathCeilingSingle_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathFloorDouble.cs b/src/tests/JIT/Intrinsics/MathFloorDouble.cs
index 5ab3db7f531dc3..e0d808a85babe6 100644
--- a/src/tests/JIT/Intrinsics/MathFloorDouble.cs
+++ b/src/tests/JIT/Intrinsics/MathFloorDouble.cs
@@ -3,10 +3,11 @@
 //
 
 using System;
+using Xunit;
 
 namespace MathFloorDoubleTest
 {
-    class Program
+    public class Program
     {
         public const int Pass = 100;
         public const int Fail = 0;
@@ -31,7 +32,8 @@ class Program
             8.8
         };
 
-        unsafe static int Main()
+        [Fact]
+        public unsafe static int TestEntryPoint()
         {
             double localValue = 9.9;
 
diff --git a/src/tests/JIT/Intrinsics/MathFloorDouble_r.csproj b/src/tests/JIT/Intrinsics/MathFloorDouble_r.csproj
index 9b670da8a42171..394c5eb0128c25 100644
--- a/src/tests/JIT/Intrinsics/MathFloorDouble_r.csproj
+++ b/src/tests/JIT/Intrinsics/MathFloorDouble_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathFloorDouble_ro.csproj b/src/tests/JIT/Intrinsics/MathFloorDouble_ro.csproj
index 180501be32448b..00b8d37a5c3ef9 100644
--- a/src/tests/JIT/Intrinsics/MathFloorDouble_ro.csproj
+++ b/src/tests/JIT/Intrinsics/MathFloorDouble_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathFloorSingle.cs b/src/tests/JIT/Intrinsics/MathFloorSingle.cs
index 711e2a0cd6f2ab..163cdc75c438a3 100644
--- a/src/tests/JIT/Intrinsics/MathFloorSingle.cs
+++ b/src/tests/JIT/Intrinsics/MathFloorSingle.cs
@@ -3,10 +3,11 @@
 //
 
 using System;
+using Xunit;
 
 namespace MathFloorSingleTest
 {
-    class Program
+    public class Program
     {
         public const int Pass = 100;
         public const int Fail = 0;
@@ -31,7 +32,8 @@ class Program
             8.8f
         };
 
-        unsafe static int Main()
+        [Fact]
+        public unsafe static int TestEntryPoint()
         {
             float localValue = 9.9f;
 
diff --git a/src/tests/JIT/Intrinsics/MathFloorSingle_r.csproj b/src/tests/JIT/Intrinsics/MathFloorSingle_r.csproj
index 1a411666623f48..893980b961aff9 100644
--- a/src/tests/JIT/Intrinsics/MathFloorSingle_r.csproj
+++ b/src/tests/JIT/Intrinsics/MathFloorSingle_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathFloorSingle_ro.csproj b/src/tests/JIT/Intrinsics/MathFloorSingle_ro.csproj
index fb5630a8050bd6..c88b3b64766cc9 100644
--- a/src/tests/JIT/Intrinsics/MathFloorSingle_ro.csproj
+++ b/src/tests/JIT/Intrinsics/MathFloorSingle_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathFusedMultiplyAdd.cs b/src/tests/JIT/Intrinsics/MathFusedMultiplyAdd.cs
index 2ef3e873e6864d..b41c91b4cd6b3f 100644
--- a/src/tests/JIT/Intrinsics/MathFusedMultiplyAdd.cs
+++ b/src/tests/JIT/Intrinsics/MathFusedMultiplyAdd.cs
@@ -6,14 +6,16 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.Intrinsics;
 using System.Runtime.Intrinsics.X86;
+using Xunit;
 
 namespace MathFusedMultiplyAddTest
 {
-    class Program
+    public class Program
     {
         private static int _returnCode = 100;
 
-        static int Main()
+        [Fact]
+        public static int TestEntryPoint()
         {
             TestFloats();
             TestDoubles();
diff --git a/src/tests/JIT/Intrinsics/MathFusedMultiplyAdd_r.csproj b/src/tests/JIT/Intrinsics/MathFusedMultiplyAdd_r.csproj
index 879a577c27c33c..d8a86ee926455e 100644
--- a/src/tests/JIT/Intrinsics/MathFusedMultiplyAdd_r.csproj
+++ b/src/tests/JIT/Intrinsics/MathFusedMultiplyAdd_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathFusedMultiplyAdd_ro.csproj b/src/tests/JIT/Intrinsics/MathFusedMultiplyAdd_ro.csproj
index c7a857e226f74e..a2d6b18d0ea379 100644
--- a/src/tests/JIT/Intrinsics/MathFusedMultiplyAdd_ro.csproj
+++ b/src/tests/JIT/Intrinsics/MathFusedMultiplyAdd_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathRoundDouble.cs b/src/tests/JIT/Intrinsics/MathRoundDouble.cs
index 591ab56f6d5dc6..2c543d92585551 100644
--- a/src/tests/JIT/Intrinsics/MathRoundDouble.cs
+++ b/src/tests/JIT/Intrinsics/MathRoundDouble.cs
@@ -3,10 +3,11 @@
 //
 
 using System;
+using Xunit;
 
 namespace MathRoundDoubleTest
 {
-    class Program
+    public class Program
     {
         public const int Pass = 100;
         public const int Fail = 0;
@@ -31,7 +32,8 @@ class Program
             8.8
         };
 
-        unsafe static int Main()
+        [Fact]
+        public unsafe static int TestEntryPoint()
         {
             double localValue = 9.9;
 
diff --git a/src/tests/JIT/Intrinsics/MathRoundDouble_r.csproj b/src/tests/JIT/Intrinsics/MathRoundDouble_r.csproj
index aadd0a40fb0c79..2073a5759be64c 100644
--- a/src/tests/JIT/Intrinsics/MathRoundDouble_r.csproj
+++ b/src/tests/JIT/Intrinsics/MathRoundDouble_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathRoundDouble_ro.csproj b/src/tests/JIT/Intrinsics/MathRoundDouble_ro.csproj
index ef13c91d0a39d2..27b84ced1daa44 100644
--- a/src/tests/JIT/Intrinsics/MathRoundDouble_ro.csproj
+++ b/src/tests/JIT/Intrinsics/MathRoundDouble_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathRoundSingle.cs b/src/tests/JIT/Intrinsics/MathRoundSingle.cs
index 8b91bedd9e8b26..0ec00f44e57365 100644
--- a/src/tests/JIT/Intrinsics/MathRoundSingle.cs
+++ b/src/tests/JIT/Intrinsics/MathRoundSingle.cs
@@ -3,10 +3,11 @@
 //
 
 using System;
+using Xunit;
 
 namespace MathRoundSingleTest
 {
-    class Program
+    public class Program
     {
         public const int Pass = 100;
         public const int Fail = 0;
@@ -31,7 +32,8 @@ class Program
             8.8f
         };
 
-        unsafe static int Main()
+        [Fact]
+        public unsafe static int TestEntryPoint()
         {
             float localValue = 9.9f;
 
diff --git a/src/tests/JIT/Intrinsics/MathRoundSingle_r.csproj b/src/tests/JIT/Intrinsics/MathRoundSingle_r.csproj
index a632f7f44b2854..9d6f20eaf75816 100644
--- a/src/tests/JIT/Intrinsics/MathRoundSingle_r.csproj
+++ b/src/tests/JIT/Intrinsics/MathRoundSingle_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MathRoundSingle_ro.csproj b/src/tests/JIT/Intrinsics/MathRoundSingle_ro.csproj
index 1795200a5c9d77..227e1514d1c40a 100644
--- a/src/tests/JIT/Intrinsics/MathRoundSingle_ro.csproj
+++ b/src/tests/JIT/Intrinsics/MathRoundSingle_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MemoryMarshalGetArrayDataReference.cs b/src/tests/JIT/Intrinsics/MemoryMarshalGetArrayDataReference.cs
index 80a1a1e53b184c..acaff504f5480c 100644
--- a/src/tests/JIT/Intrinsics/MemoryMarshalGetArrayDataReference.cs
+++ b/src/tests/JIT/Intrinsics/MemoryMarshalGetArrayDataReference.cs
@@ -8,14 +8,16 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Runtime.Intrinsics;
+using Xunit;
 
 namespace MemoryMarshalGetArrayDataReferenceTest
 {
-    class Program
+    public class Program
     {
         private static int _errors = 0;
 
-        unsafe static int Main(string[] args)
+        [Fact]
+        public unsafe static int TestEntryPoint()
         {
             // use no inline methods to avoid indirect call inlining in the future
             [MethodImpl(MethodImplOptions.NoInlining)]
diff --git a/src/tests/JIT/Intrinsics/MemoryMarshalGetArrayDataReference_r.csproj b/src/tests/JIT/Intrinsics/MemoryMarshalGetArrayDataReference_r.csproj
index 35ced7827ac9d6..1dc9ac2cff5699 100644
--- a/src/tests/JIT/Intrinsics/MemoryMarshalGetArrayDataReference_r.csproj
+++ b/src/tests/JIT/Intrinsics/MemoryMarshalGetArrayDataReference_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/MemoryMarshalGetArrayDataReference_ro.csproj b/src/tests/JIT/Intrinsics/MemoryMarshalGetArrayDataReference_ro.csproj
index ed3dda49d893ff..93f48533953a73 100644
--- a/src/tests/JIT/Intrinsics/MemoryMarshalGetArrayDataReference_ro.csproj
+++ b/src/tests/JIT/Intrinsics/MemoryMarshalGetArrayDataReference_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
diff --git a/src/tests/JIT/Intrinsics/TypeEquality.cs b/src/tests/JIT/Intrinsics/TypeEquality.cs
index 009891fdead7c1..7c5abef2809380 100644
--- a/src/tests/JIT/Intrinsics/TypeEquality.cs
+++ b/src/tests/JIT/Intrinsics/TypeEquality.cs
@@ -4,6 +4,7 @@
 
 using System;
 using System.Runtime.CompilerServices;
+using Xunit;
 
 // Optimization of type equality tests to various
 // vtable and handle comparisons.
@@ -50,9 +51,10 @@ public static bool Is<P,Q>()
    }
 }
 
-class P
+public class P
 {
-   public static int Main()
+   [Fact]
+   public static int TestEntryPoint()
    {   
       bool passed = true;
 
diff --git a/src/tests/JIT/Intrinsics/TypeEqualitySealed.cs b/src/tests/JIT/Intrinsics/TypeEqualitySealed.cs
index c7d90091273554..d6c22c8868865f 100644
--- a/src/tests/JIT/Intrinsics/TypeEqualitySealed.cs
+++ b/src/tests/JIT/Intrinsics/TypeEqualitySealed.cs
@@ -4,6 +4,7 @@
 
 using System;
 using System.Runtime.CompilerServices;
+using Xunit;
 
 // Make sure optimization works correctly under GT_JTRUE and GT_RETURN nodes
 // Also, if it respects/preserves side-effects and doesn't optimize away
@@ -89,7 +90,8 @@ public static class Program
 {
     private static int returnCode = 100;
 
-    public static int Main()
+    [Fact]
+    public static int TestEntryPoint()
     {
         var tests = new SealedClass1();
         AssertEquals("Ok", tests.TestTernary1());
diff --git a/src/tests/JIT/Intrinsics/TypeEqualitySealed_r.csproj b/src/tests/JIT/Intrinsics/TypeEqualitySealed_r.csproj
index f616891de94df2..60796f9068e0f2 100644
--- a/src/tests/JIT/Intrinsics/TypeEqualitySealed_r.csproj
+++ b/src/tests/JIT/Intrinsics/TypeEqualitySealed_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <DebugType>None</DebugType>
     <Optimize />
   </PropertyGroup>
diff --git a/src/tests/JIT/Intrinsics/TypeEqualitySealed_ro.csproj b/src/tests/JIT/Intrinsics/TypeEqualitySealed_ro.csproj
index 1a391262f8fe8c..d27568518ef448 100644
--- a/src/tests/JIT/Intrinsics/TypeEqualitySealed_ro.csproj
+++ b/src/tests/JIT/Intrinsics/TypeEqualitySealed_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <DebugType>None</DebugType>
     <Optimize>True</Optimize>
   </PropertyGroup>
diff --git a/src/tests/JIT/Intrinsics/TypeEquality_r.csproj b/src/tests/JIT/Intrinsics/TypeEquality_r.csproj
index 2e353c5b939beb..1806e19f5b40ae 100644
--- a/src/tests/JIT/Intrinsics/TypeEquality_r.csproj
+++ b/src/tests/JIT/Intrinsics/TypeEquality_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <DebugType>None</DebugType>
     <Optimize />
   </PropertyGroup>
diff --git a/src/tests/JIT/Intrinsics/TypeEquality_ro.csproj b/src/tests/JIT/Intrinsics/TypeEquality_ro.csproj
index 71027d743f9e1f..8ebdc22102c3f5 100644
--- a/src/tests/JIT/Intrinsics/TypeEquality_ro.csproj
+++ b/src/tests/JIT/Intrinsics/TypeEquality_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <DebugType>None</DebugType>
     <Optimize>True</Optimize>
   </PropertyGroup>
diff --git a/src/tests/JIT/Intrinsics/TypeIntrinsics.cs b/src/tests/JIT/Intrinsics/TypeIntrinsics.cs
index e54069c4e082ed..7a0b27d1a7b33a 100644
--- a/src/tests/JIT/Intrinsics/TypeIntrinsics.cs
+++ b/src/tests/JIT/Intrinsics/TypeIntrinsics.cs
@@ -7,12 +7,14 @@
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 using System.Runtime.Intrinsics;
+using Xunit;
 
 public partial class Program
 {
     private static int _errors = 0;
 
-    public static int Main()
+    [Fact]
+    public static int TestEntryPoint()
     {
         IsTrue (typeof(byte).IsValueType);
         IsTrue (typeof(int).IsValueType);
diff --git a/src/tests/JIT/Intrinsics/TypeIntrinsics_il.il b/src/tests/JIT/Intrinsics/TypeIntrinsics_il.il
index 51696870df98b5..4927bf7897e8da 100644
--- a/src/tests/JIT/Intrinsics/TypeIntrinsics_il.il
+++ b/src/tests/JIT/Intrinsics/TypeIntrinsics_il.il
@@ -7,10 +7,10 @@
 
 .assembly 'TypeIntrinsics_il' { }
 
-.class private auto ansi beforefieldinit Test_TypeIntrinsics_il
+.class public auto ansi beforefieldinit Test_TypeIntrinsics_il
        extends [mscorlib]System.Object
 {
-  .method private hidebysig static int32 Main() cil managed
+  .method public hidebysig static int32 Main() cil managed
   {
     .custom instance void [xunit.core]Xunit.FactAttribute::.ctor() = (
         01 00 00 00
diff --git a/src/tests/JIT/Intrinsics/TypeIntrinsics_il.ilproj b/src/tests/JIT/Intrinsics/TypeIntrinsics_il.ilproj
index 0f82ec220c766a..fac591ab0e3398 100644
--- a/src/tests/JIT/Intrinsics/TypeIntrinsics_il.ilproj
+++ b/src/tests/JIT/Intrinsics/TypeIntrinsics_il.ilproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.IL">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <DebugType>PdbOnly</DebugType>
diff --git a/src/tests/JIT/Intrinsics/TypeIntrinsics_r.csproj b/src/tests/JIT/Intrinsics/TypeIntrinsics_r.csproj
index 8a556ce073ac10..9a4d1574929fd1 100644
--- a/src/tests/JIT/Intrinsics/TypeIntrinsics_r.csproj
+++ b/src/tests/JIT/Intrinsics/TypeIntrinsics_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <DebugType>None</DebugType>
     <Optimize />
   </PropertyGroup>
diff --git a/src/tests/JIT/Intrinsics/TypeIntrinsics_ro.csproj b/src/tests/JIT/Intrinsics/TypeIntrinsics_ro.csproj
index 4b1c989578015e..1bbf2cf5874a36 100644
--- a/src/tests/JIT/Intrinsics/TypeIntrinsics_ro.csproj
+++ b/src/tests/JIT/Intrinsics/TypeIntrinsics_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <DebugType>None</DebugType>
     <Optimize>True</Optimize>
   </PropertyGroup>
diff --git a/src/tests/JIT/JIT_RemoveMergedTests.projitems b/src/tests/JIT/JIT_RemoveMergedTests.projitems
new file mode 100644
index 00000000000000..69f2e01707f689
--- /dev/null
+++ b/src/tests/JIT/JIT_RemoveMergedTests.projitems
@@ -0,0 +1,15 @@
+<Project>
+  <ItemGroup>
+    <MergedWrapperProjectReference Remove="CodeGenBringUpTests/**/*.??proj" />
+    <MergedWrapperProjectReference Remove="Directed/**/*.??proj" />
+    <MergedWrapperProjectReference Remove="Generics/**/*.??proj" />
+    <MergedWrapperProjectReference Remove="HardwareIntrinsics/**/*.??proj" />
+    <MergedWrapperProjectReference Remove="IL_Conformance/**/*.??proj" />
+    <MergedWrapperProjectReference Remove="jit64/**/*.??proj" />
+    <MergedWrapperProjectReference Remove="Methodical/**/*.??proj" />
+    <MergedWrapperProjectReference Remove="opt/**/*.??proj" />
+    <MergedWrapperProjectReference Remove="Performance/**/*.??proj" />
+    <MergedWrapperProjectReference Remove="Regression/**/*.??proj" />
+    <MergedWrapperProjectReference Remove="SIMD/**/*.??proj" />
+  </ItemGroup>
+</Project>
diff --git a/src/tests/JIT/JIT_d.csproj b/src/tests/JIT/JIT_d.csproj
new file mode 100644
index 00000000000000..97c15a35243f35
--- /dev/null
+++ b/src/tests/JIT/JIT_d.csproj
@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <ItemGroup>
+    <MergedWrapperProjectReference Include="*/**/*_d.??proj" />
+  </ItemGroup>
+
+  <Import Project="JIT_RemoveMergedTests.projitems" />
+  <Import Project="$(TestSourceDir)MergedTestRunner.targets" />
+</Project>
diff --git a/src/tests/JIT/JIT_do.csproj b/src/tests/JIT/JIT_do.csproj
new file mode 100644
index 00000000000000..e9c29ed33c3b5b
--- /dev/null
+++ b/src/tests/JIT/JIT_do.csproj
@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <ItemGroup>
+    <MergedWrapperProjectReference Include="*/**/*_do.??proj" />
+  </ItemGroup>
+
+  <Import Project="JIT_RemoveMergedTests.projitems" />
+  <Import Project="$(TestSourceDir)MergedTestRunner.targets" />
+</Project>
diff --git a/src/tests/JIT/JIT_others.csproj b/src/tests/JIT/JIT_others.csproj
new file mode 100644
index 00000000000000..8468055a1f87f8
--- /dev/null
+++ b/src/tests/JIT/JIT_others.csproj
@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <ItemGroup>
+    <MergedWrapperProjectReference Include="*/**/*.??proj" />
+
+    <MergedWrapperProjectReference Remove="*/**/*_d.??proj" />
+    <MergedWrapperProjectReference Remove="*/**/*_do.??proj" />
+    <MergedWrapperProjectReference Remove="*/**/*_r.??proj" />
+    <MergedWrapperProjectReference Remove="*/**/*_ro.??proj" />
+  </ItemGroup>
+
+  <Import Project="JIT_RemoveMergedTests.projitems" />
+  <Import Project="$(TestSourceDir)MergedTestRunner.targets" />
+</Project>
diff --git a/src/tests/JIT/JIT_r.csproj b/src/tests/JIT/JIT_r.csproj
new file mode 100644
index 00000000000000..37f495002e38be
--- /dev/null
+++ b/src/tests/JIT/JIT_r.csproj
@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <ItemGroup>
+    <MergedWrapperProjectReference Include="*/**/*_r.??proj" />
+  </ItemGroup>
+
+  <Import Project="JIT_RemoveMergedTests.projitems" />
+  <Import Project="$(TestSourceDir)MergedTestRunner.targets" />
+</Project>
diff --git a/src/tests/JIT/JIT_ro.csproj b/src/tests/JIT/JIT_ro.csproj
new file mode 100644
index 00000000000000..69b4b80b80a819
--- /dev/null
+++ b/src/tests/JIT/JIT_ro.csproj
@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <ItemGroup>
+    <MergedWrapperProjectReference Include="*/**/*_ro.??proj" />
+  </ItemGroup>
+
+  <Import Project="JIT_RemoveMergedTests.projitems" />
+  <Import Project="$(TestSourceDir)MergedTestRunner.targets" />
+</Project>
diff --git a/src/tests/JIT/Math/Functions/Functions_r.csproj b/src/tests/JIT/Math/Functions/Functions_r.csproj
index e61a28a885d851..44117a40803742 100644
--- a/src/tests/JIT/Math/Functions/Functions_r.csproj
+++ b/src/tests/JIT/Math/Functions/Functions_r.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <DebugType>None</DebugType>
diff --git a/src/tests/JIT/Math/Functions/Functions_ro.csproj b/src/tests/JIT/Math/Functions/Functions_ro.csproj
index 87bd76c30b2001..53798703bac2be 100644
--- a/src/tests/JIT/Math/Functions/Functions_ro.csproj
+++ b/src/tests/JIT/Math/Functions/Functions_ro.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
   </PropertyGroup>
   <PropertyGroup>
     <DebugType>None</DebugType>
diff --git a/src/tests/JIT/Math/Functions/Program.cs b/src/tests/JIT/Math/Functions/Program.cs
index 71c868e87848a1..98ac1ef18dbd57 100644
--- a/src/tests/JIT/Math/Functions/Program.cs
+++ b/src/tests/JIT/Math/Functions/Program.cs
@@ -1,11 +1,13 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using Xunit;
 namespace System.MathBenchmarks
 {
     public partial class MathTests
     {
-        public static int Main()
+        [Fact]
+        public static int TestEntryPoint()
         {
             var result = 100;
 
diff --git a/src/tests/JIT/Methodical/Directory.Build.props b/src/tests/JIT/Methodical/Directory.Build.props
index 02a2c0eb2f6b60..eaafc60fa2f0ae 100644
--- a/src/tests/JIT/Methodical/Directory.Build.props
+++ b/src/tests/JIT/Methodical/Directory.Build.props
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\Directory.Merged.props" />
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props, $(MSBuildThisFileDirectory)..))" />
 
   <PropertyGroup>
diff --git a/src/tests/JIT/PGO/InstrumentedTiers/InstrumentedTiers.cs b/src/tests/JIT/PGO/InstrumentedTiers/InstrumentedTiers.cs
index f3705502e9967c..b0d5f0e0edd5bb 100644
--- a/src/tests/JIT/PGO/InstrumentedTiers/InstrumentedTiers.cs
+++ b/src/tests/JIT/PGO/InstrumentedTiers/InstrumentedTiers.cs
@@ -4,11 +4,13 @@
 using System;
 using System.Runtime.CompilerServices;
 using System.Threading;
+using Xunit;
 
 // A smoke test for all DOTNET_TieredPGO strategies
-class Program : IDisposable
+public class Program : IDisposable
 {
-    static int Main()
+    [Fact]
+    public static void TestEntryPoint()
     {
         Program p = new();
         for (int i = 0; i < 100; i++)
@@ -16,7 +18,6 @@ static int Main()
             HotLoop(p);
             Thread.Sleep(40); // cold loop
         }
-        return 100;
     }
 
     [MethodImpl(MethodImplOptions.NoInlining)]
diff --git a/src/tests/JIT/PGO/InstrumentedTiers/InstrumentedTiers.csproj b/src/tests/JIT/PGO/InstrumentedTiers/InstrumentedTiers.csproj
index 9cd1526a84fe7e..6be4544c89f84b 100644
--- a/src/tests/JIT/PGO/InstrumentedTiers/InstrumentedTiers.csproj
+++ b/src/tests/JIT/PGO/InstrumentedTiers/InstrumentedTiers.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for CLRTestBatchEnvironmentVariable -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <Optimize>True</Optimize>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst.cs b/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst.cs
index 3b48f7d462d16b..a1bf8b31f054f1 100644
--- a/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst.cs
+++ b/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst.cs
@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 using System.Threading;
+using Xunit;
 
 public interface IInterface { }
 public interface IGenericInterface<T> { }
@@ -73,7 +74,8 @@ static bool AssertEquals<T>(T t1, T t2)
         return EqualityComparer<T>.Default.Equals(t1, t2);
     }
 
-    public static int Main()
+    [Fact]
+    public static void TestEntryPoint()
     {
         var a = new ClassA();
         var b = new ClassB();
@@ -209,6 +211,5 @@ public static int Main()
 
             Thread.Sleep(20);
         }
-        return 100;
     }
 }
diff --git a/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst.csproj b/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst.csproj
index a3f43ad5bf2388..8fe8133989f50e 100644
--- a/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst.csproj
+++ b/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for CLRTestEnvironmentVariable -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <Optimize>True</Optimize>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst_random1.csproj b/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst_random1.csproj
index d03a5fd3df4d80..00a88fd50167d2 100644
--- a/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst_random1.csproj
+++ b/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst_random1.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for CLRTestEnvironmentVariable -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <Optimize>True</Optimize>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst_random2.csproj b/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst_random2.csproj
index c2efc8780d1121..346bb467e37d2c 100644
--- a/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst_random2.csproj
+++ b/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst_random2.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for CLRTestEnvironmentVariable -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <Optimize>True</Optimize>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst_random3.csproj b/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst_random3.csproj
index dc0d8ac53da449..d054f5504e7680 100644
--- a/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst_random3.csproj
+++ b/src/tests/JIT/PGO/ProfileCastClassAndIsInst/ProfileCastClassAndIsInst_random3.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for CLRTestEnvironmentVariable -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <Optimize>True</Optimize>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/tests/JIT/Performance/Directory.Build.props b/src/tests/JIT/Performance/Directory.Build.props
index 689ebf8db31e1a..8f1448d9f2db2d 100644
--- a/src/tests/JIT/Performance/Directory.Build.props
+++ b/src/tests/JIT/Performance/Directory.Build.props
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
-  <Import Project="..\..\Directory.Merged.props" />
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props, $(MSBuildThisFileDirectory)..))" />
 
   <PropertyGroup>
diff --git a/src/tests/JIT/Regression/Directory.Build.props b/src/tests/JIT/Regression/Directory.Build.props
index fd98cb087403e3..843a760db1a8ce 100644
--- a/src/tests/JIT/Regression/Directory.Build.props
+++ b/src/tests/JIT/Regression/Directory.Build.props
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
-  <Import Project="..\..\Directory.Merged.props" />
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props, $(MSBuildThisFileDirectory)..))" />
 
   <PropertyGroup>
diff --git a/src/tests/JIT/RyuJIT/DoWhileBndChk.cs b/src/tests/JIT/RyuJIT/DoWhileBndChk.cs
index 9ba5a944f8adee..36797b31adcae5 100644
--- a/src/tests/JIT/RyuJIT/DoWhileBndChk.cs
+++ b/src/tests/JIT/RyuJIT/DoWhileBndChk.cs
@@ -9,11 +9,13 @@
 
 using System;
 using System.Runtime.ExceptionServices;
+using Xunit;
 
 public class Program
 {
     [HandleProcessCorruptedStateExceptions]
-    public static int Main()
+    [Fact]
+    public static int TestEntryPoint()
     {
         int ret = 99;
 
diff --git a/src/tests/JIT/RyuJIT/DoWhileBndChk.csproj b/src/tests/JIT/RyuJIT/DoWhileBndChk.csproj
index d73b427b40bc2a..4dc2a5f1facd3c 100644
--- a/src/tests/JIT/RyuJIT/DoWhileBndChk.csproj
+++ b/src/tests/JIT/RyuJIT/DoWhileBndChk.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
     <Optimize>True</Optimize>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/tests/JIT/SIMD/Directory.Build.props b/src/tests/JIT/SIMD/Directory.Build.props
index 689ebf8db31e1a..8f1448d9f2db2d 100644
--- a/src/tests/JIT/SIMD/Directory.Build.props
+++ b/src/tests/JIT/SIMD/Directory.Build.props
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
-  <Import Project="..\..\Directory.Merged.props" />
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props, $(MSBuildThisFileDirectory)..))" />
 
   <PropertyGroup>
diff --git a/src/tests/JIT/Stress/ABI/pinvokes_d.csproj b/src/tests/JIT/Stress/ABI/pinvokes_d.csproj
index a8e9f135a89bf5..734e0a53fdd348 100644
--- a/src/tests/JIT/Stress/ABI/pinvokes_d.csproj
+++ b/src/tests/JIT/Stress/ABI/pinvokes_d.csproj
@@ -1,6 +1,12 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for GCStressIncompatible, JitOptimizationSensitive -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
+
+    <!-- Main supports command-line arguments -->
+    <ReferenceXUnitWrapperGenerator>false</ReferenceXUnitWrapperGenerator>
+    <CLRTestExecutionArguments>--pinvokes --num-calls 1000 --no-ctrlc-summary</CLRTestExecutionArguments>
+
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
     <JitOptimizationSensitive>true</JitOptimizationSensitive>
     <GCStressIncompatible>true</GCStressIncompatible>
@@ -8,7 +14,6 @@
   <PropertyGroup>
     <DebugType>Full</DebugType>
     <Optimize>False</Optimize>
-    <CLRTestExecutionArguments>--pinvokes --num-calls 1000 --no-ctrlc-summary</CLRTestExecutionArguments>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="*.cs" />
diff --git a/src/tests/JIT/Stress/ABI/pinvokes_do.csproj b/src/tests/JIT/Stress/ABI/pinvokes_do.csproj
index d0a3fec2c3ea0f..309cb73d7b11e1 100644
--- a/src/tests/JIT/Stress/ABI/pinvokes_do.csproj
+++ b/src/tests/JIT/Stress/ABI/pinvokes_do.csproj
@@ -1,6 +1,12 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for GCStressIncompatible, JitOptimizationSensitive -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
+
+    <!-- Main supports command-line arguments -->
+    <ReferenceXUnitWrapperGenerator>false</ReferenceXUnitWrapperGenerator>
+    <CLRTestExecutionArguments>--pinvokes --num-calls 1000 --no-ctrlc-summary</CLRTestExecutionArguments>
+
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
     <JitOptimizationSensitive>true</JitOptimizationSensitive>
     <GCStressIncompatible>true</GCStressIncompatible>
@@ -8,7 +14,6 @@
   <PropertyGroup>
     <DebugType>Full</DebugType>
     <Optimize>True</Optimize>
-    <CLRTestExecutionArguments>--pinvokes --num-calls 1000 --no-ctrlc-summary</CLRTestExecutionArguments>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="*.cs" />
diff --git a/src/tests/JIT/Stress/ABI/stubs_do.csproj b/src/tests/JIT/Stress/ABI/stubs_do.csproj
index 3e03d223e1cbbb..074d268462d20b 100644
--- a/src/tests/JIT/Stress/ABI/stubs_do.csproj
+++ b/src/tests/JIT/Stress/ABI/stubs_do.csproj
@@ -1,6 +1,12 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for GCStressIncompatible, JitOptimizationSensitive -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
+
+    <!-- Main supports command-line arguments -->
+    <ReferenceXUnitWrapperGenerator>false</ReferenceXUnitWrapperGenerator>
+    <CLRTestExecutionArguments>--instantiatingstubs --unboxingstubs --sharedgenericunboxingstubs --num-calls 100 --max-params 5 --no-ctrlc-summary</CLRTestExecutionArguments>
+
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
     <JitOptimizationSensitive>true</JitOptimizationSensitive>
     <GCStressIncompatible>true</GCStressIncompatible>
@@ -8,7 +14,6 @@
   <PropertyGroup>
     <DebugType>Full</DebugType>
     <Optimize>True</Optimize>
-    <CLRTestExecutionArguments>--instantiatingstubs --unboxingstubs --sharedgenericunboxingstubs --num-calls 100 --max-params 5 --no-ctrlc-summary</CLRTestExecutionArguments>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="*.cs" />
diff --git a/src/tests/JIT/Stress/ABI/tailcalls_d.csproj b/src/tests/JIT/Stress/ABI/tailcalls_d.csproj
index bf3a37f1538992..f4a41e649c4bcd 100644
--- a/src/tests/JIT/Stress/ABI/tailcalls_d.csproj
+++ b/src/tests/JIT/Stress/ABI/tailcalls_d.csproj
@@ -1,6 +1,12 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for GCStressIncompatible, JitOptimizationSensitive -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
+
+    <!-- Main supports command-line arguments -->
+    <ReferenceXUnitWrapperGenerator>false</ReferenceXUnitWrapperGenerator>
+    <CLRTestExecutionArguments>--tailcalls --num-calls 1000 --no-ctrlc-summary</CLRTestExecutionArguments>
+
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
     <JitOptimizationSensitive>true</JitOptimizationSensitive>
     <GCStressIncompatible>true</GCStressIncompatible>
@@ -8,7 +14,6 @@
   <PropertyGroup>
     <DebugType>Full</DebugType>
     <Optimize>False</Optimize>
-    <CLRTestExecutionArguments>--tailcalls --num-calls 1000 --no-ctrlc-summary</CLRTestExecutionArguments>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="*.cs" />
diff --git a/src/tests/JIT/Stress/ABI/tailcalls_do.csproj b/src/tests/JIT/Stress/ABI/tailcalls_do.csproj
index b8ba35aff4fcef..c295fce88b56d3 100644
--- a/src/tests/JIT/Stress/ABI/tailcalls_do.csproj
+++ b/src/tests/JIT/Stress/ABI/tailcalls_do.csproj
@@ -1,6 +1,12 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for GCStressIncompatible, JitOptimizationSensitive -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
+
+    <!-- Main supports command-line arguments -->
+    <ReferenceXUnitWrapperGenerator>false</ReferenceXUnitWrapperGenerator>
+    <CLRTestExecutionArguments>--tailcalls --num-calls 1000 --no-ctrlc-summary</CLRTestExecutionArguments>
+
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
     <JitOptimizationSensitive>true</JitOptimizationSensitive>
     <GCStressIncompatible>true</GCStressIncompatible>
@@ -8,7 +14,6 @@
   <PropertyGroup>
     <DebugType>Full</DebugType>
     <Optimize>True</Optimize>
-    <CLRTestExecutionArguments>--tailcalls --num-calls 1000 --no-ctrlc-summary</CLRTestExecutionArguments>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="*.cs" />
diff --git a/src/tests/JIT/jit64/Directory.Build.props b/src/tests/JIT/jit64/Directory.Build.props
index 689ebf8db31e1a..8f1448d9f2db2d 100644
--- a/src/tests/JIT/jit64/Directory.Build.props
+++ b/src/tests/JIT/jit64/Directory.Build.props
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
-  <Import Project="..\..\Directory.Merged.props" />
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props, $(MSBuildThisFileDirectory)..))" />
 
   <PropertyGroup>
diff --git a/src/tests/JIT/opt/Directory.Build.props b/src/tests/JIT/opt/Directory.Build.props
index fd98cb087403e3..843a760db1a8ce 100644
--- a/src/tests/JIT/opt/Directory.Build.props
+++ b/src/tests/JIT/opt/Directory.Build.props
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
-  <Import Project="..\..\Directory.Merged.props" />
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props, $(MSBuildThisFileDirectory)..))" />
 
   <PropertyGroup>
diff --git a/src/tests/JIT/superpmi/superpmicollect.csproj b/src/tests/JIT/superpmi/superpmicollect.csproj
index 19a068885a9896..df3d304510a3cc 100644
--- a/src/tests/JIT/superpmi/superpmicollect.csproj
+++ b/src/tests/JIT/superpmi/superpmicollect.csproj
@@ -1,6 +1,11 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- Needed for GCStressIncompatible, UnloadabilityIncompatible, JitOptimizationSensitive, IlasmRoundTripIncompatible -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
+
+    <!-- This test uses very custom execution logic including explicit Main -->
+    <ReferenceXUnitWrapperGenerator>false</ReferenceXUnitWrapperGenerator>
+
     <!-- ilasm round-trip testing works, but is not interesting for this test:
          we already get round-trip testing for the referenced projects, so doing
          it here only adds round-trip testing of the harness, as well as doing