diff --git a/CHANGELOG-PRERELEASE.md b/CHANGELOG-PRERELEASE.md
index d00bcc301..c93ccd1e1 100644
--- a/CHANGELOG-PRERELEASE.md
+++ b/CHANGELOG-PRERELEASE.md
@@ -10,6 +10,8 @@ The format is based on [Keep a Changelog].
 ### Added
 
 ### Changed
+- BlendShape Weight mismatch warning is now build-time warning instad of validate time warning `#359`
+  - Thanks to FreeseBlendShape by TraceAndOptimize, most pre-build this warning is false positive. So this warning is moved to build-time only.
 
 ### Deprecated
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 965a6728b..5186577ec 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,8 @@ The format is based on [Keep a Changelog].
 
 ## [Unreleased]
 ### Added
+- BlendShape Weight mismatch warning is now build-time warning instad of validate time warning `#359`
+  - Thanks to FreeseBlendShape by TraceAndOptimize, most pre-build this warning is false positive. So this warning is moved to build-time only.
 
 ### Changed
 
diff --git a/Editor/MergeSkinnedMeshEditor.cs b/Editor/MergeSkinnedMeshEditor.cs
index a1bbd9344..8cfe5766e 100644
--- a/Editor/MergeSkinnedMeshEditor.cs
+++ b/Editor/MergeSkinnedMeshEditor.cs
@@ -34,12 +34,6 @@ static MergeSkinnedMeshEditor()
                 if (component.GetComponent<SkinnedMeshRenderer>().sharedMesh)
                     err.Add(ErrorLog.Warning("MergeSkinnedMesh:warning:MeshIsNotNone"));
 
-                err.AddRange(component.renderersSet.GetAsSet()
-                    .SelectMany(EditSkinnedMeshComponentUtil.GetBlendShapes)
-                    .GroupBy(x => x.name, x => x.weight)
-                    .Where(grouping => grouping.Distinct().Count() != 1)
-                    .Select(grouping => ErrorLog.Warning("MergeSkinnedMesh:warning:blendShapeWeightMismatch", grouping.Key)));
-
                 return err;
             });
         }
@@ -69,13 +63,6 @@ protected override void OnInspectorGUIInner()
             {
                 EditorGUILayout.HelpBox(CL4EE.Tr("MergeSkinnedMesh:warning:MeshIsNotNone"), MessageType.Warning);
             }
-            
-            foreach (var grouping in component.renderersSet.GetAsSet()
-                         .SelectMany(EditSkinnedMeshComponentUtil.GetBlendShapes)
-                         .GroupBy(x => x.name, x => x.weight)
-                         .Where(grouping => grouping.Distinct().Count() != 1))
-                EditorGUILayout.HelpBox(string.Format(CL4EE.Tr("MergeSkinnedMesh:warning:blendShapeWeightMismatch"), grouping.Key),
-                    MessageType.Warning);
 
             EditorGUILayout.PropertyField(_renderersSetProp);
             EditorGUILayout.PropertyField(_staticRenderersSetProp);
diff --git a/Editor/Processors/EditSkinnedMeshComponentProcessor.cs b/Editor/Processors/EditSkinnedMeshComponentProcessor.cs
index cdf6650a8..a3de3876a 100644
--- a/Editor/Processors/EditSkinnedMeshComponentProcessor.cs
+++ b/Editor/Processors/EditSkinnedMeshComponentProcessor.cs
@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Linq;
+using Anatawa12.AvatarOptimizer.ErrorReporting;
 using Anatawa12.AvatarOptimizer.Processors.SkinnedMeshes;
 using UnityEngine;
 
@@ -24,7 +25,7 @@ public void Process(OptimizerSession session)
                 foreach (var processor in processors.GetSorted())
                 {
                     // TODO
-                    processor.Process(session, target, holder);
+                    BuildReport.ReportingObject(processor.Component, () => processor.Process(session, target, holder));
                     target.AssertInvariantContract(
                         $"after {processor.GetType().Name} " +
                         $"for {processor.Target.gameObject.name}");
diff --git a/Editor/Processors/SkinnedMeshes/MergeSkinnedMeshProcessor.cs b/Editor/Processors/SkinnedMeshes/MergeSkinnedMeshProcessor.cs
index a1b91f697..3e353524e 100644
--- a/Editor/Processors/SkinnedMeshes/MergeSkinnedMeshProcessor.cs
+++ b/Editor/Processors/SkinnedMeshes/MergeSkinnedMeshProcessor.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using Anatawa12.AvatarOptimizer.ErrorReporting;
 using UnityEngine;
 using Object = UnityEngine.Object;
 
@@ -40,6 +41,7 @@ TexCoordStatus TexCoordStatusMax(TexCoordStatus x, TexCoordStatus y) =>
             var newBoundMax = Vector3.negativeInfinity;
 
             var mappings = new List<(string, string)>();
+            var weightMismatchBlendShapes = new HashSet<string>();
 
             for (var i = 0; i < meshInfos.Length; i++)
             {
@@ -72,6 +74,12 @@ TexCoordStatus TexCoordStatusMax(TexCoordStatus x, TexCoordStatus y) =>
                         newIndex = target.BlendShapes.Count;
                         target.BlendShapes.Add((name, weight));
                     }
+                    else
+                    {
+                        // ReSharper disable once CompareOfFloatsByEqualityOperator
+                        if (weight != target.BlendShapes[newIndex].weight)
+                            weightMismatchBlendShapes.Add(name);
+                    }
 
                     mappings.Add((VProp.BlendShapeIndex(sourceI), VProp.BlendShapeIndex(newIndex)));
                 }
@@ -103,6 +111,9 @@ TexCoordStatus TexCoordStatusMax(TexCoordStatus x, TexCoordStatus y) =>
                 target.AssertInvariantContract($"processing meshInfo {Target.gameObject.name}");
             }
 
+            foreach (var weightMismatchBlendShape in weightMismatchBlendShapes)
+                BuildReport.LogWarning("MergeSkinnedMesh:warning:blendShapeWeightMismatch", weightMismatchBlendShape);
+
             if (updateBounds && newBoundMin != Vector3.positiveInfinity && newBoundMax != Vector3.negativeInfinity)
             {
                 target.Bounds.SetMinMax(newBoundMin, newBoundMax);
diff --git a/Internal/ErrorReporter/Editor/BuildReport.cs b/Internal/ErrorReporter/Editor/BuildReport.cs
index e86c47c4a..9da77970b 100644
--- a/Internal/ErrorReporter/Editor/BuildReport.cs
+++ b/Internal/ErrorReporter/Editor/BuildReport.cs
@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Reflection;
 using System.Runtime.CompilerServices;
 using JetBrains.Annotations;
 using UnityEditor;
@@ -127,11 +128,11 @@ internal AvatarReport Initialize(VRCAvatarDescriptor descriptor)
         }
 
         [CanBeNull]
-        internal static ErrorLog Log(ReportLevel level, string code, params string[] strings)
+        internal static ErrorLog Log(ReportLevel level, string code, string[] strings, Assembly assembly)
         {
             for (var i = 0; i < strings.Length; i++)
                 strings[i] = strings[i] ?? "";
-            var errorLog = new ErrorLog(level, code, strings);
+            var errorLog = new ErrorLog(level, code, strings, assembly);
 
             var avatarReport = CurrentReport.CurrentAvatar;
             if (avatarReport == null)
@@ -144,10 +145,18 @@ internal static ErrorLog Log(ReportLevel level, string code, params string[] str
             return errorLog;
         }
 
+        [CanBeNull]
+        public static ErrorLog LogInfo(string code, params string[] strings) => Log(ReportLevel.Info, code,
+            strings: strings, assembly: Assembly.GetCallingAssembly());
+
+        [CanBeNull]
+        public static ErrorLog LogWarning(string code, params string[] strings) => Log(ReportLevel.Warning, code,
+            strings: strings, assembly: Assembly.GetCallingAssembly());
+
         [CanBeNull]
         public static ErrorLog LogFatal(string code, params string[] strings)
         {
-            var log = Log(ReportLevel.Error, code, strings: strings);
+            var log = Log(ReportLevel.Error, code, strings: strings, assembly: Assembly.GetCallingAssembly());
             if (CurrentReport.CurrentAvatar != null)
             {
                 CurrentReport.CurrentAvatar.successful = false;