diff --git a/src/skate3_native_scene_gpu.cpp b/src/skate3_native_scene_gpu.cpp
index ec4b1dd..b527c9f 100644
--- a/src/skate3_native_scene_gpu.cpp
+++ b/src/skate3_native_scene_gpu.cpp
@@ -6801,6 +6801,7 @@ bool RenderShadowAtlas(const NativeGuestOutputRenderContext& context,
         cmd->ClearRenderTarget(g_r.world_shadow, ws_clear);
         std::memcpy(g_r.world_shadow_rows, scene.dynobj_ws,
                     sizeof(g_r.world_shadow_rows));
+        g_r.world_shadow_drawn.clear();
         if (!g_r.world_shadow_primed) {
           REXLOG_INFO(
               "native-scene: world-shadow map primed (dynobj c5/c6/c7 rows)");
@@ -6843,6 +6844,21 @@ bool RenderShadowAtlas(const NativeGuestOutputRenderContext& context,
         if (mit == g_r.meshes.end()) {
           continue;
         }
+        // Accumulate each item exactly once per map generation: MIN-blend
+        // re-draws are idempotent, so anything already in the map is pure
+        // redundant work (the whole static item list re-rendered every 4th
+        // frame paced this pass). Keyed on mesh + content fingerprint +
+        // world transform; an in-place content swap or a moved instance
+        // reads as new and lands on the next accumulation frame.
+        uint64_t ws_key = 1469598103934665603ull ^ item.mesh;
+        ws_key = (ws_key ^ mit->second.fingerprint) * 1099511628211ull;
+        const uint8_t* wb = reinterpret_cast<const uint8_t*>(item.world);
+        for (size_t bi = 0; bi < sizeof(item.world); ++bi) {
+          ws_key = (ws_key ^ wb[bi]) * 1099511628211ull;
+        }
+        if (!g_r.world_shadow_drawn.insert(ws_key).second) {
+          continue;
+        }
         float constants[52] = {};
         std::memcpy(constants, item.world, sizeof(item.world));
         float* mvp = constants + 16;
diff --git a/src/skate3_native_scene_gpu_internal.h b/src/skate3_native_scene_gpu_internal.h
index bbceecf..5003a3a 100644
--- a/src/skate3_native_scene_gpu_internal.h
+++ b/src/skate3_native_scene_gpu_internal.h
@@ -8,6 +8,8 @@
 
 #include "skate3_native_scene_state.h"
 
+#include <unordered_set>
+
 #if (defined(REX_HAS_D3D12) && REX_HAS_D3D12) || (defined(REX_HAS_VULKAN) && REX_HAS_VULKAN)
 
 #include <rex/graphics/native_guest_renderer.h>
@@ -915,6 +917,13 @@ struct RendererState {
   bool world_shadow_primed = false;
   float world_shadow_rows[12] = {};
   static constexpr uint32_t kWorldShadowSize = 512;
+  // Items already accumulated into the current map (mesh + world-transform
+  // hash): MIN-blend re-draws of the same geometry are idempotent, so each
+  // static item needs to land exactly once per map generation. The periodic
+  // accumulation pass then only draws newly streamed/decoded items (normally
+  // zero) instead of the whole static item list. Reset on re-prime (clear).
+  // Render thread only.
+  std::unordered_set<uint64_t> world_shadow_drawn;
   static constexpr uint32_t kUiRegionSize = 1u << 20;
   static constexpr uint32_t kUiRegions = 8;
   nrhi::Buffer* ui_ring = nullptr;
diff --git a/third_party/rexglue-sdk b/third_party/rexglue-sdk
index 17caf72..41dd2d5 160000
--- a/third_party/rexglue-sdk
+++ b/third_party/rexglue-sdk
@@ -1 +1 @@
-Subproject commit 17caf72bddd25a91500436e4df5a32a00a259d73
+Subproject commit 41dd2d5cb4a2648f667365a7984a520959e644a6