diff --git a/MobileGL/MG_State/GLState/ProgramState/ProgramLinkTask.cpp b/MobileGL/MG_State/GLState/ProgramState/ProgramLinkTask.cpp
index bffc2083..32547df1 100644
--- a/MobileGL/MG_State/GLState/ProgramState/ProgramLinkTask.cpp
+++ b/MobileGL/MG_State/GLState/ProgramState/ProgramLinkTask.cpp
@@ -909,6 +909,19 @@ namespace MobileGL::MG_State::GLState {
                 artifacts.generatedSpirv.size());
 
         // Linked SPIR-V generated, sanitize and optimize it
+        {
+            // TEMP-STAGE-PROBE: "spirv-null" - the same Optimizer::Run with ZERO passes,
+            // on the pre-optimize binary: pure BuildModule + serialize + IRContext
+            // teardown. Its device/desktop share ratio against "spirv-opt" is the
+            // allocator-pathology discriminator. Costs one extra plumbing round per
+            // module; diagnostic build only.
+            const MG_Util::Debug::TempStageProbeScope tempStageProbeSpirvNull(
+                MG_Util::Debug::kTempStageProbeSpirvNull);
+            for (auto& spv : artifacts.generatedSpirv) {
+                Vector<uint32_t> nullOut;
+                (void)ShaderCompiler::TempProbeNullOptimizeBinary(spv, nullOut);
+            }
+        }
         {
             // TEMP-STAGE-PROBE: "spirv-opt" - the spirv-tools optimizer run over every module.
             const MG_Util::Debug::TempStageProbeScope tempStageProbeSpirvOpt(
diff --git a/MobileGL/MG_Util/Debug/TempStageProbe.h b/MobileGL/MG_Util/Debug/TempStageProbe.h
index 9537e5cf..e69cac4e 100644
--- a/MobileGL/MG_Util/Debug/TempStageProbe.h
+++ b/MobileGL/MG_Util/Debug/TempStageProbe.h
@@ -31,6 +31,7 @@ namespace MobileGL::MG_Util::Debug {
         kTempStageProbeParseReparse,
         kTempStageProbeGlslangLink,
         kTempStageProbeSpirvGen,
+        kTempStageProbeSpirvNull,
         kTempStageProbeSpirvOpt,
         kTempStageProbeReflection,
         kTempStageProbeSpvcRouting,
@@ -45,6 +46,7 @@ namespace MobileGL::MG_Util::Debug {
         "parse-reparse[subset-of-parse]",
         "glslang-link",
         "spirv-gen",
+        "spirv-null[plumbing-only]",
         "spirv-opt",
         "reflection",
         "spvc-routing",
diff --git a/MobileGL/MG_Util/ShaderTranspiler/ShaderCompiler.cpp b/MobileGL/MG_Util/ShaderTranspiler/ShaderCompiler.cpp
index 27baf7ff..f9898098 100644
--- a/MobileGL/MG_Util/ShaderTranspiler/ShaderCompiler.cpp
+++ b/MobileGL/MG_Util/ShaderTranspiler/ShaderCompiler.cpp
@@ -385,6 +385,19 @@ namespace MobileGL {
                 return optimizer.Run(inputBinary.data(), inputBinary.size(), &outputBinary, options);
             }
 
+            // TEMP-STAGE-PROBE tempStageProbeNullOptimize: SanitizeAndOptimizeBinary minus
+            // every pass - measures the pure IR plumbing (BuildModule + serialize +
+            // IRContext teardown) so a device run can separate allocator-bound plumbing
+            // from transformation work. Remove with the probes.
+            bool ShaderCompiler::TempProbeNullOptimizeBinary(const Vector<Uint32>& inputBinary,
+                                                             Vector<uint32_t>& outputBinary) {
+                using namespace spvtools;
+                OptimizerOptions options;
+                options.set_run_validator(false);
+                Optimizer optimizer(SPV_ENV_VULKAN_1_1);
+                return optimizer.Run(inputBinary.data(), inputBinary.size(), &outputBinary, options);
+            }
+
             bool ShaderCompiler::LowerDrawParametersForEssl(const Vector<Uint32>& inputBinary,
                                                             Vector<uint32_t>& outputBinary) {
                 using namespace spvtools;
diff --git a/MobileGL/MG_Util/ShaderTranspiler/ShaderCompiler.h b/MobileGL/MG_Util/ShaderTranspiler/ShaderCompiler.h
index bd1a5964..450b4863 100644
--- a/MobileGL/MG_Util/ShaderTranspiler/ShaderCompiler.h
+++ b/MobileGL/MG_Util/ShaderTranspiler/ShaderCompiler.h
@@ -22,6 +22,10 @@ namespace MobileGL {
                 static Result<Vector<Vector<unsigned>>> GetSpirvBinaryFromProgram(const ProgramBinaryAttrib& attrib);
                 static bool SanitizeAndOptimizeBinary(const Vector<Uint32>& inputBinary,
                                                       Vector<uint32_t>& outputBinary);
+                // TEMP-STAGE-PROBE: SanitizeAndOptimizeBinary with zero passes - pure IR
+                // plumbing, for the allocator-pathology discriminator. Remove with the probes.
+                static bool TempProbeNullOptimizeBinary(const Vector<Uint32>& inputBinary,
+                                                        Vector<uint32_t>& outputBinary);
                 // Demotes DrawIndex/BaseInstance/BaseVertex builtins to plain Private globals
                 // (mg_DrawID/mg_BaseInstance/mg_BaseVertex) so SPIRV-Cross can emit ESSL.
                 // Only for backends without native draw-parameter support (DirectGLES).