diff --git a/WeaveLoaderRuntime/src/HookManager.cpp b/WeaveLoaderRuntime/src/HookManager.cpp
index 848fe19..9b2537a 100644
--- a/WeaveLoaderRuntime/src/HookManager.cpp
+++ b/WeaveLoaderRuntime/src/HookManager.cpp
@@ -21,11 +21,13 @@ bool HookManager::Install(const SymbolResolver& symbols)
     }
 
     WorldIdRemap::SetTagNewTagSymbol(symbols.pTagNewTag);
+    WorldIdRemap::SetTileArraySymbol(symbols.pTileTiles);
     WorldIdRemap::SetLevelChunkTileSymbols(
         symbols.pLevelChunkGetTile,
         symbols.pLevelChunkSetTile,
         symbols.pLevelChunkGetPos,
         symbols.pLevelChunkGetHighestNonEmptyY);
+    WorldIdRemap::SetCompressedTileStorageSetSymbol(symbols.pCompressedTileStorageSet);
 
     if (symbols.pRunStaticCtors)
     {
diff --git a/WeaveLoaderRuntime/src/PdbParser.cpp b/WeaveLoaderRuntime/src/PdbParser.cpp
index 4f92440..d6b0aaa 100644
--- a/WeaveLoaderRuntime/src/PdbParser.cpp
+++ b/WeaveLoaderRuntime/src/PdbParser.cpp
@@ -16,6 +16,8 @@
 #include "PDB_CoalescedMSFStream.h"
 #include "PDB_ModuleInfoStream.h"
 #include "PDB_ModuleSymbolStream.h"
+#include "PDB_Util.h"
+#include "Foundation/PDB_BitUtil.h"
 
 struct SymEntry
 {
@@ -188,7 +190,15 @@ static uint32_t ResolveProcRefRVA(uint16_t moduleIndex, uint32_t symbolOffset)
         const PDB::ModuleSymbolStream modSymStream = mod.CreateSymbolStream(*s_rawFile);
         for (uint32_t candidateOffset : candidateOffsets)
         {
-            const PDB::CodeView::DBI::Record* target = modSymStream.GetRecordAtOffset(candidateOffset);
+            const PDB::CodeView::DBI::Record* target = nullptr;
+            size_t currentOffset = sizeof(uint32_t);
+            modSymStream.ForEachSymbol([&](const PDB::CodeView::DBI::Record* record) {
+                if (target == nullptr && currentOffset == static_cast<size_t>(candidateOffset))
+                    target = record;
+                const uint32_t recordSize = PDB::GetCodeViewRecordSize(record);
+                currentOffset = PDB::BitUtil::RoundUpToMultiple<size_t>(
+                    currentOffset + sizeof(PDB::CodeView::DBI::RecordHeader) + recordSize, 4u);
+            });
             const uint32_t rva = ResolveProcRecordRVA(target, s_sectionStream);
             if (rva != 0)
                 return rva;
diff --git a/WeaveLoaderRuntime/src/SymbolResolver.cpp b/WeaveLoaderRuntime/src/SymbolResolver.cpp
index 4d6883c..021aa68 100644
--- a/WeaveLoaderRuntime/src/SymbolResolver.cpp
+++ b/WeaveLoaderRuntime/src/SymbolResolver.cpp
@@ -263,6 +263,7 @@ bool SymbolResolver::ResolveGameFunctions()
     pLevelChunkSetTile = ResolveExactProcName(m_moduleBase, "LevelChunk::setTile");
     pLevelChunkGetPos = ResolveExactProcName(m_moduleBase, "LevelChunk::getPos");
     pLevelChunkGetHighestNonEmptyY = ResolveExactProcName(m_moduleBase, "LevelChunk::getHighestNonEmptyY");
+    pCompressedTileStorageSet = ResolveExactProcName(m_moduleBase, "CompressedTileStorage::set");
 
     // Some public symbols in this build resolve to stub bodies. Prefer exact
     // module procedure names from the PDB where those exist.
@@ -380,6 +381,7 @@ bool SymbolResolver::ResolveGameFunctions()
     logSym("LevelChunk::setTile", pLevelChunkSetTile);
     logSym("LevelChunk::getPos", pLevelChunkGetPos);
     logSym("LevelChunk::getHighestNonEmptyY", pLevelChunkGetHighestNonEmptyY);
+    logSym("CompressedTileStorage::set", pCompressedTileStorageSet);
 
     bool ok = pRunStaticCtors && pMinecraftTick && pMinecraftInit;
     if (ok)
diff --git a/WeaveLoaderRuntime/src/SymbolResolver.h b/WeaveLoaderRuntime/src/SymbolResolver.h
index ad35c73..3c33036 100644
--- a/WeaveLoaderRuntime/src/SymbolResolver.h
+++ b/WeaveLoaderRuntime/src/SymbolResolver.h
@@ -100,6 +100,7 @@ public:
     void* pLevelChunkSetTile = nullptr;          // LevelChunk::setTile(int,int,int,int)
     void* pLevelChunkGetPos = nullptr;           // LevelChunk::getPos()
     void* pLevelChunkGetHighestNonEmptyY = nullptr; // LevelChunk::getHighestNonEmptyY()
+    void* pCompressedTileStorageSet = nullptr;        // CompressedTileStorage::set(int,int,int,int)
 
 private:
     uintptr_t m_moduleBase = 0;
diff --git a/WeaveLoaderRuntime/src/WorldIdRemap.cpp b/WeaveLoaderRuntime/src/WorldIdRemap.cpp
index 6bcbdb5..63fd5af 100644
--- a/WeaveLoaderRuntime/src/WorldIdRemap.cpp
+++ b/WeaveLoaderRuntime/src/WorldIdRemap.cpp
@@ -20,10 +20,10 @@
 namespace
 {
     constexpr wchar_t kNamespaceTagKey[] = L"weaveloader:id";
+    constexpr wchar_t kNamespaceKindTagKey[] = L"weaveloader:kind";
     constexpr char kMissingBlockId[] = "weaveloader:missing_block";
     constexpr char kMissingItemId[] = "weaveloader:missing_item";
-    constexpr int kMissingBlockNumericId = 255;
-    constexpr int kMissingItemNumericId = 31999;
+    constexpr int kMissingBlockVanillaFallbackId = 7; // bedrock
     constexpr int kMissingBlockDescriptionId = 900000;
     constexpr int kMissingItemDescriptionId = 900001;
     constexpr ptrdiff_t kItemIdOffset = 0x20;
@@ -38,6 +38,7 @@ namespace
     using LevelChunkSetTile_fn = bool (__fastcall *)(void* thisPtr, int x, int y, int z, int tile);
     using LevelChunkGetPos_fn = void* (__fastcall *)(void* thisPtr);
     using LevelChunkGetHighestNonEmptyY_fn = int (__fastcall *)(void* thisPtr);
+    using CompressedTileStorageSet_fn = void (__fastcall *)(void* thisPtr, int x, int y, int z, int val);
 
     struct CompoundTagLayout
     {
@@ -55,10 +56,15 @@ namespace
 
     std::once_flag s_symbolInitOnce;
     TagNewTag_fn s_tagNewTag = nullptr;
+    void* s_tileArray = nullptr;
     LevelChunkGetTile_fn s_levelChunkGetTile = nullptr;
     LevelChunkSetTile_fn s_levelChunkSetTile = nullptr;
     LevelChunkGetPos_fn s_levelChunkGetPos = nullptr;
     LevelChunkGetHighestNonEmptyY_fn s_levelChunkGetHighestNonEmptyY = nullptr;
+    CompressedTileStorageSet_fn s_compressedTileStorageSet = nullptr;
+
+    // LevelChunk layout: vtable(8) + byteArray(16) = 24, then lowerBlocks at 24, upperBlocks at 32
+    static constexpr size_t kLevelChunkLowerBlocksOffset = 24;
     bool s_missingPlaceholdersReady = false;
     int s_chunkRemapLogCount = 0;
     int s_chunkSaveLogCount = 0;
@@ -72,6 +78,8 @@ namespace
         int z = 0;
     };
     std::unordered_map<void*, ChunkMeta> s_chunkMetaByPtr;
+    std::unordered_map<void*, std::unordered_map<int, std::string>> s_loadedNamespaceByChunk;
+    std::unordered_map<std::string, std::unordered_map<int, std::string>> s_chunkNamespaceCache;
 
     struct ConsoleSavePathLayout
     {
@@ -104,7 +112,6 @@ namespace
         virtual int closeHandle(void* fileEntry) = 0;
         virtual void finalizeWrite() = 0;
         virtual void tick() = 0;
-        virtual bool doesFileExist(ConsoleSavePathLayout fileName) = 0;
     };
 
     struct RuntimeFileEntryLayout
@@ -122,17 +129,20 @@ namespace
         return storagePtr && IsReadableRange(storagePtr, sizeof(void*) + sizeof(std::wstring) + sizeof(void*));
     }
 
-    static std::wstring MakeChunkNamespacePath(const McRegionChunkStorageLayout* storage, int chunkX, int chunkZ)
+    static std::wstring MakeChunkNamespacePathCoordsOnly(int chunkX, int chunkZ)
     {
         std::wstringstream ss;
-        std::hash<std::wstring> hasher;
-        const size_t prefixHash = hasher(storage ? storage->prefix : std::wstring());
-        ss << L"modloader\\blockns\\"
-           << std::hex << prefixHash << std::dec
-           << L"\\c." << chunkX << L"." << chunkZ << L".txt";
+        ss << L"modloader\\blockns_v3\\c." << chunkX << L"." << chunkZ << L".txt";
         return ss.str();
     }
 
+    static std::string MakeChunkCacheKey(const McRegionChunkStorageLayout* storage, int chunkX, int chunkZ)
+    {
+        const std::wstring path = MakeChunkNamespacePathCoordsOnly(chunkX, chunkZ);
+        std::string key(path.begin(), path.end());
+        return key;
+    }
+
     static bool SaveReadAllText(void* saveFile, const std::wstring& path, std::string* outText)
     {
         if (!saveFile || !outText || !IsReadableRange(saveFile, sizeof(void*)))
@@ -145,11 +155,18 @@ namespace
             return false;
         save->setFilePointer(fileEntry, 0, nullptr, FILE_BEGIN);
 
-        unsigned int fileSize = 0;
-        if (IsReadableRange(fileEntry, sizeof(RuntimeFileEntryLayout)))
+        if (!IsReadableRange(fileEntry, sizeof(RuntimeFileEntryLayout)))
         {
-            const auto* entry = reinterpret_cast<const RuntimeFileEntryLayout*>(fileEntry);
-            fileSize = entry->length;
+            save->closeHandle(fileEntry);
+            return false;
+        }
+        const auto* entry = reinterpret_cast<const RuntimeFileEntryLayout*>(fileEntry);
+        const unsigned int fileSize = entry->length;
+        // Hard cap for corrupted metadata; chunk namespace files should stay tiny.
+        if (fileSize > (1024u * 1024u))
+        {
+            save->closeHandle(fileEntry);
+            return false;
         }
 
         std::string text;
@@ -171,15 +188,6 @@ namespace
         return true;
     }
 
-    static bool SaveFileExists(void* saveFile, const std::wstring& path)
-    {
-        if (!saveFile || !IsReadableRange(saveFile, sizeof(void*)))
-            return false;
-        auto* save = reinterpret_cast<RuntimeConsoleSaveFile*>(saveFile);
-        ConsoleSavePathLayout savePath(path);
-        return save->doesFileExist(savePath);
-    }
-
     static bool SaveWriteAllText(void* saveFile, const std::wstring& path, const std::string& text)
     {
         if (!saveFile || !IsReadableRange(saveFile, sizeof(void*)))
@@ -198,6 +206,11 @@ namespace
         return ok && bytesWritten == text.size();
     }
 
+    static bool WriteChunkNamespaceMap(
+        void* saveFile,
+        const std::wstring& path,
+        const std::unordered_map<int, std::string>& map);
+
     static bool ReadChunkNamespaceMap(
         void* saveFile,
         const std::wstring& path,
@@ -207,9 +220,6 @@ namespace
             return false;
         outMap->clear();
 
-        if (!SaveFileExists(saveFile, path))
-            return false;
-
         std::string text;
         if (!SaveReadAllText(saveFile, path, &text))
             return false;
@@ -244,9 +254,46 @@ namespace
             if (expectedEntries >= 0 && parsedEntries >= expectedEntries)
                 break;
         }
+        if (expectedEntries < 0)
+        {
+            // Require explicit count header for safety; legacy files can contain stale tail bytes.
+            outMap->clear();
+            return false;
+        }
         return true;
     }
 
+    static bool IsLikelyNamespacedId(const std::string& s)
+    {
+        if (s.size() < 3 || s.size() > 200)
+            return false;
+        if (s.find(':') == std::string::npos)
+            return false;
+        for (char c : s)
+        {
+            if (c <= 0x20 || c == '\x7f')
+                return false;
+        }
+        return true;
+    }
+
+    static bool ReadChunkNamespaceMapWithFallback(
+        const McRegionChunkStorageLayout* storage,
+        int chunkX,
+        int chunkZ,
+        std::unordered_map<int, std::string>* outMap)
+    {
+        if (!storage || !storage->saveFile || !outMap)
+            return false;
+        outMap->clear();
+
+        // Preferred stable path that does not depend on object layout/prefix decoding.
+        const std::wstring v3Path = MakeChunkNamespacePathCoordsOnly(chunkX, chunkZ);
+        if (ReadChunkNamespaceMap(storage->saveFile, v3Path, outMap) && !outMap->empty())
+            return true;
+        return false;
+    }
+
     static bool WriteChunkNamespaceMap(
         void* saveFile,
         const std::wstring& path,
@@ -294,6 +341,26 @@ namespace
         meta.z = chunkZ;
     }
 
+    static void SetLoadedChunkNamespaces(void* chunkPtr, const std::unordered_map<int, std::string>& entries)
+    {
+        if (!chunkPtr)
+            return;
+        std::lock_guard<std::mutex> lock(s_chunkMetaMutex);
+        s_loadedNamespaceByChunk[chunkPtr] = entries;
+    }
+
+    static bool TryGetLoadedChunkNamespaces(void* chunkPtr, std::unordered_map<int, std::string>* outEntries)
+    {
+        if (!chunkPtr || !outEntries)
+            return false;
+        std::lock_guard<std::mutex> lock(s_chunkMetaMutex);
+        const auto it = s_loadedNamespaceByChunk.find(chunkPtr);
+        if (it == s_loadedNamespaceByChunk.end())
+            return false;
+        *outEntries = it->second;
+        return true;
+    }
+
     static bool TryResolveChunkCoords(void* levelChunkPtr, int* outX, int* outZ)
     {
         if (!levelChunkPtr || !s_levelChunkGetPos)
@@ -307,11 +374,103 @@ namespace
         return true;
     }
 
+    static bool IsValidRuntimeTileId(int tileId)
+    {
+        if (tileId == 0)
+            return true;
+        if (tileId < 0 || tileId > 255)
+            return false;
+        if (!s_tileArray || !IsReadableRange(s_tileArray, sizeof(void*)))
+            return true; // can't validate, don't aggressively rewrite
+
+        // Tile::tiles is a global Tile** pointer variable in this build.
+        // Symbol points at the variable, so dereference once to get the actual table.
+        auto** tiles = *reinterpret_cast<void***>(s_tileArray);
+        if (!tiles || !IsReadableRange(tiles, sizeof(void*) * 256))
+            return true; // can't validate safely
+
+        return tiles[tileId] != nullptr;
+    }
+
     static bool IsVanillaId(const std::string& namespacedId)
     {
         return namespacedId.rfind("minecraft:", 0) == 0;
     }
 
+    static int ResolveSafeMissingBlockFallbackId()
+    {
+        int fallbackId = IdRegistry::Instance().GetMissingFallback(IdRegistry::Type::Block);
+        if (IsValidRuntimeTileId(fallbackId))
+            return fallbackId;
+        const int missingBlockId = IdRegistry::Instance().GetNumericId(IdRegistry::Type::Block, kMissingBlockId);
+        if (IsValidRuntimeTileId(missingBlockId))
+            return missingBlockId;
+        if (IsValidRuntimeTileId(kMissingBlockVanillaFallbackId))
+            return kMissingBlockVanillaFallbackId;
+        if (IsValidRuntimeTileId(1))
+            return 1;
+        return 0;
+    }
+
+    static bool IsTilePointerValid(int tileId)
+    {
+        if (tileId == 0)
+            return true;
+        if (tileId < 0 || tileId > 255)
+            return false;
+        if (!s_tileArray || !IsReadableRange(s_tileArray, sizeof(void*)))
+            return true;
+        auto** tiles = *reinterpret_cast<void***>(s_tileArray);
+        if (!tiles || !IsReadableRange(tiles, sizeof(void*) * 256))
+            return true;
+        return tiles[tileId] != nullptr;
+    }
+
+    static bool SafeSetChunkTile(void* levelChunkPtr, int x, int y, int z, int tileId)
+    {
+        if (!s_levelChunkSetTile)
+            return false;
+
+        // If the current block has no valid Tile pointer, setTileAndData will crash when it
+        // calls Tile::tiles[old]->onRemoving. Clear it to air first via direct block storage write.
+        if (s_levelChunkGetTile && s_compressedTileStorageSet && levelChunkPtr && IsReadableRange(levelChunkPtr, kLevelChunkLowerBlocksOffset + 16))
+        {
+#if defined(_MSC_VER)
+            __try
+            {
+                int current = s_levelChunkGetTile(levelChunkPtr, x, y, z);
+                if (current != 0 && !IsTilePointerValid(current))
+                {
+                    void* blocksPtr = *reinterpret_cast<void**>(static_cast<char*>(levelChunkPtr) + (y >= 128 ? kLevelChunkLowerBlocksOffset + 8 : kLevelChunkLowerBlocksOffset));
+                    if (blocksPtr && IsReadableRange(blocksPtr, sizeof(void*)))
+                    {
+                        s_compressedTileStorageSet(blocksPtr, x, y % 128, z, 0);
+                    }
+                }
+            }
+            __except (EXCEPTION_EXECUTE_HANDLER)
+            {
+                // Ignore - we'll try setTile anyway
+            }
+#endif
+        }
+
+#if defined(_MSC_VER)
+        __try
+        {
+            s_levelChunkSetTile(levelChunkPtr, x, y, z, tileId);
+            return true;
+        }
+        __except (EXCEPTION_EXECUTE_HANDLER)
+        {
+            return false;
+        }
+#else
+        s_levelChunkSetTile(levelChunkPtr, x, y, z, tileId);
+        return true;
+#endif
+    }
+
     static std::string ResolveNamespacedItemId(int numericId)
     {
         std::string namespacedId = IdRegistry::Instance().GetStringId(IdRegistry::Type::Item, numericId);
@@ -322,7 +481,7 @@ namespace
         return IdRegistry::Instance().GetStringId(IdRegistry::Type::Block, numericId);
     }
 
-    static int ResolveNumericItemId(const std::string& namespacedId, int oldNumericId)
+    static int ResolveNumericItemId(const std::string& namespacedId, int oldNumericId, const std::wstring& kind = L"")
     {
         if (namespacedId.empty())
             return -1;
@@ -345,7 +504,7 @@ namespace
         if (blockId >= 0)
             return blockId;
 
-        if (wasKnownAsBlock)
+        if (wasKnownAsBlock || kind == L"block")
             return IdRegistry::Instance().GetMissingFallback(IdRegistry::Type::Block);
 
         return IdRegistry::Instance().GetMissingFallback(IdRegistry::Type::Item);
@@ -456,11 +615,18 @@ namespace
 
 namespace WorldIdRemap
 {
+    static thread_local int s_remapStage = 0;
+
     void SetTagNewTagSymbol(void* fnPtr)
     {
         s_tagNewTag = reinterpret_cast<TagNewTag_fn>(fnPtr);
     }
 
+    void SetTileArraySymbol(void* tileArrayPtr)
+    {
+        s_tileArray = tileArrayPtr;
+    }
+
     void SetLevelChunkTileSymbols(void* getTileFn, void* setTileFn, void* getPosFn, void* getHighestNonEmptyYFn)
     {
         s_levelChunkGetTile = reinterpret_cast<LevelChunkGetTile_fn>(getTileFn);
@@ -469,35 +635,51 @@ namespace WorldIdRemap
         s_levelChunkGetHighestNonEmptyY = reinterpret_cast<LevelChunkGetHighestNonEmptyY_fn>(getHighestNonEmptyYFn);
     }
 
+    void SetCompressedTileStorageSetSymbol(void* setFn)
+    {
+        s_compressedTileStorageSet = reinterpret_cast<CompressedTileStorageSet_fn>(setFn);
+    }
+
     void EnsureMissingPlaceholders()
     {
         if (s_missingPlaceholdersReady)
             return;
 
-        IdRegistry::Instance().RegisterVanilla(IdRegistry::Type::Block, kMissingBlockNumericId, kMissingBlockId);
-        IdRegistry::Instance().RegisterVanilla(IdRegistry::Type::Item, kMissingItemNumericId, kMissingItemId);
+        const int missingBlockId = IdRegistry::Instance().Register(IdRegistry::Type::Block, kMissingBlockId);
+        const int missingItemId = IdRegistry::Instance().Register(IdRegistry::Type::Item, kMissingItemId);
 
-        ModStrings::Register(kMissingBlockDescriptionId, L"Missing Block");
-        GameObjectFactory::CreateTile(
-            kMissingBlockNumericId,
-            1,
-            1.0f,
-            1.0f,
-            1,
-            L"bedrock",
-            0.0f,
-            15,
-            kMissingBlockDescriptionId);
-        IdRegistry::Instance().SetMissingFallback(IdRegistry::Type::Block, kMissingBlockNumericId);
+        if (missingBlockId < 0)
+            LogUtil::Log("[WeaveLoader] Failed to register missing block placeholder (no free block IDs)");
+        if (missingItemId < 0)
+            LogUtil::Log("[WeaveLoader] Failed to register missing item placeholder (no free item IDs)");
 
-        ModStrings::Register(kMissingItemDescriptionId, L"Missing Item");
-        GameObjectFactory::CreateItem(
-            kMissingItemNumericId,
-            64,
-            0,
-            L"apple",
-            kMissingItemDescriptionId);
-        IdRegistry::Instance().SetMissingFallback(IdRegistry::Type::Item, kMissingItemNumericId);
+        if (missingBlockId >= 0)
+        {
+            ModStrings::Register(kMissingBlockDescriptionId, L"Missing Block");
+            GameObjectFactory::CreateTile(
+                missingBlockId,
+                1,
+                1.0f,
+                1.0f,
+                1,
+                L"bedrock",
+                0.0f,
+                15,
+                kMissingBlockDescriptionId);
+            IdRegistry::Instance().SetMissingFallback(IdRegistry::Type::Block, missingBlockId);
+        }
+
+        if (missingItemId >= 0)
+        {
+            ModStrings::Register(kMissingItemDescriptionId, L"Missing Item");
+            GameObjectFactory::CreateItem(
+                missingItemId,
+                64,
+                0,
+                L"apple",
+                kMissingItemDescriptionId);
+            IdRegistry::Instance().SetMissingFallback(IdRegistry::Type::Item, missingItemId);
+        }
 
         s_missingPlaceholdersReady = true;
         LogUtil::Log("[WeaveLoader] Missing content placeholders ready: block=%d item=%d",
@@ -505,8 +687,9 @@ namespace WorldIdRemap
                      IdRegistry::Instance().GetMissingFallback(IdRegistry::Type::Item));
     }
 
-    int RemapChunkBlockIds(void* chunkStoragePtr, void* levelChunkPtr, int chunkX, int chunkZ)
+    static int RemapChunkBlockIdsImpl(void* chunkStoragePtr, void* levelChunkPtr, int chunkX, int chunkZ)
     {
+        s_remapStage = 1;
         if (!chunkStoragePtr || !levelChunkPtr || !s_levelChunkGetTile || !s_levelChunkSetTile)
             return 0;
         if (!IsValidChunkStorage(chunkStoragePtr))
@@ -519,37 +702,87 @@ namespace WorldIdRemap
         SetChunkMeta(levelChunkPtr, chunkStoragePtr, chunkX, chunkZ);
 
         std::unordered_map<int, std::string> entries;
-        const std::wstring path = MakeChunkNamespacePath(storage, chunkX, chunkZ);
-        if (!SaveFileExists(storage->saveFile, path))
-            return 0;
+        const std::string cacheKey = MakeChunkCacheKey(storage, chunkX, chunkZ);
+        {
+            std::lock_guard<std::mutex> lock(s_chunkMetaMutex);
+            const auto cacheIt = s_chunkNamespaceCache.find(cacheKey);
+            if (cacheIt != s_chunkNamespaceCache.end())
+                entries = cacheIt->second;
+        }
         if (s_chunkIoLogCount < 32)
         {
             ++s_chunkIoLogCount;
             LogUtil::Log("[WeaveLoader] WorldIdRemap blocks: reading chunk namespace map x=%d z=%d", chunkX, chunkZ);
         }
-        if (!ReadChunkNamespaceMap(storage->saveFile, path, &entries) || entries.empty())
-            return 0;
+        if (entries.empty())
+        {
+            s_remapStage = 2;
+            if (ReadChunkNamespaceMapWithFallback(storage, chunkX, chunkZ, &entries) && !entries.empty())
+            {
+                std::lock_guard<std::mutex> lock(s_chunkMetaMutex);
+                s_chunkNamespaceCache[cacheKey] = entries;
+            }
+        }
+        if (!entries.empty())
+            SetLoadedChunkNamespaces(levelChunkPtr, entries);
+
+        const int sanitizeFallbackId = ResolveSafeMissingBlockFallbackId();
+        int applyMaxY = 127;
+        if (s_levelChunkGetHighestNonEmptyY)
+        {
+            const int highestY = s_levelChunkGetHighestNonEmptyY(levelChunkPtr);
+            if (highestY >= 0 && highestY < kChunkMaxY)
+            {
+                int bound = highestY + 16;
+                if (bound >= kChunkMaxY)
+                    bound = kChunkMaxY - 1;
+                applyMaxY = bound;
+            }
+            else if (highestY >= 0)
+            {
+                applyMaxY = kChunkMaxY - 1;
+            }
+        }
+
+        if (applyMaxY > 127)
+            applyMaxY = 127;
 
-        const int missingBlockFallback = IdRegistry::Instance().GetMissingFallback(IdRegistry::Type::Block);
         int changed = 0;
+        int skippedInvalid = 0;
+        int writeExceptions = 0;
+        s_remapStage = 3;
         for (const auto& entry : entries)
         {
             int x = 0;
             int y = 0;
             int z = 0;
             DecodeBlockIndex(entry.first, &x, &y, &z);
+            if (y < 0 || y > applyMaxY)
+            {
+                ++skippedInvalid;
+                continue;
+            }
+            if (!IsLikelyNamespacedId(entry.second))
+            {
+                ++skippedInvalid;
+                continue;
+            }
             int newId = IdRegistry::Instance().GetNumericId(IdRegistry::Type::Block, entry.second);
             if (newId < 0)
-                newId = missingBlockFallback;
+                newId = sanitizeFallbackId;
+            if (!IsValidRuntimeTileId(newId))
+                newId = sanitizeFallbackId;
             if (newId < 0 || newId > 255)
-                continue;
-
-            const int oldId = s_levelChunkGetTile(levelChunkPtr, x, y, z);
-            if (newId != oldId)
             {
-                s_levelChunkSetTile(levelChunkPtr, x, y, z, newId);
-                ++changed;
+                ++skippedInvalid;
+                continue;
             }
+            if (!SafeSetChunkTile(levelChunkPtr, x, y, z, newId))
+            {
+                ++writeExceptions;
+                continue;
+            }
+            ++changed;
         }
 
         if (changed > 0 && s_chunkRemapLogCount < 64)
@@ -557,9 +790,37 @@ namespace WorldIdRemap
             ++s_chunkRemapLogCount;
             LogUtil::Log("[WeaveLoader] WorldIdRemap blocks: remapped %d block ids in chunk", changed);
         }
+        if (skippedInvalid > 0 && s_chunkRemapLogCount < 64)
+        {
+            ++s_chunkRemapLogCount;
+            LogUtil::Log("[WeaveLoader] WorldIdRemap blocks: skipped %d invalid namespace entries in chunk", skippedInvalid);
+        }
+        if (writeExceptions > 0 && s_chunkRemapLogCount < 64)
+        {
+            ++s_chunkRemapLogCount;
+            LogUtil::Log("[WeaveLoader] WorldIdRemap blocks: skipped %d writes due to setTile exceptions", writeExceptions);
+        }
+        s_remapStage = 0;
         return changed;
     }
 
+    int RemapChunkBlockIds(void* chunkStoragePtr, void* levelChunkPtr, int chunkX, int chunkZ)
+    {
+#if defined(_MSC_VER)
+        __try
+        {
+            return RemapChunkBlockIdsImpl(chunkStoragePtr, levelChunkPtr, chunkX, chunkZ);
+        }
+        __except(EXCEPTION_EXECUTE_HANDLER)
+        {
+            LogUtil::Log("[WeaveLoader] WorldIdRemap blocks: exception while remapping chunk x=%d z=%d stage=%d (skipped)", chunkX, chunkZ, s_remapStage);
+            return 0;
+        }
+#else
+        return RemapChunkBlockIdsImpl(chunkStoragePtr, levelChunkPtr, chunkX, chunkZ);
+#endif
+    }
+
     void SaveChunkBlockNamespaces(void* chunkStoragePtr, void* levelChunkPtr)
     {
         if (!chunkStoragePtr || !levelChunkPtr || !s_levelChunkGetTile)
@@ -580,18 +841,18 @@ namespace WorldIdRemap
             SetChunkMeta(levelChunkPtr, chunkStoragePtr, meta.x, meta.z);
         }
 
-        const std::wstring path = MakeChunkNamespacePath(storage, meta.x, meta.z);
-        const bool hadExistingMap = SaveFileExists(storage->saveFile, path);
-        std::unordered_map<int, std::string> previousEntries;
-        if (hadExistingMap)
-            ReadChunkNamespaceMap(storage->saveFile, path, &previousEntries);
+        const std::wstring path = MakeChunkNamespacePathCoordsOnly(meta.x, meta.z);
+        const std::string cacheKey = MakeChunkCacheKey(storage, meta.x, meta.z);
+        std::unordered_map<int, std::string> loadedEntries;
+        const bool hadLoadedMap = TryGetLoadedChunkNamespaces(levelChunkPtr, &loadedEntries) && !loadedEntries.empty();
 
         std::unordered_map<int, std::string> nextEntries;
+        const int missingBlockFallback = IdRegistry::Instance().GetMissingFallback(IdRegistry::Type::Block);
         int maxY = kChunkMaxY - 1;
         if (s_levelChunkGetHighestNonEmptyY)
         {
             const int highestY = s_levelChunkGetHighestNonEmptyY(levelChunkPtr);
-            if (highestY < 0 && !hadExistingMap)
+            if (highestY < 0 && !hadLoadedMap)
                 return;
             if (highestY >= 0 && highestY < kChunkMaxY)
                 maxY = highestY;
@@ -604,18 +865,32 @@ namespace WorldIdRemap
                 for (int x = 0; x < kChunkWidth; ++x)
                 {
                     const int blockId = s_levelChunkGetTile(levelChunkPtr, x, y, z);
+                    const int blockIndex = MakeBlockIndex(x, y, z);
+
+                    if (blockId == missingBlockFallback)
+                    {
+                        const auto loadedIt = loadedEntries.find(blockIndex);
+                        if (loadedIt != loadedEntries.end() && !loadedIt->second.empty() && loadedIt->second != kMissingBlockId)
+                        {
+                            nextEntries[blockIndex] = loadedIt->second;
+                            continue;
+                        }
+                        continue;
+                    }
+
                     std::string namespacedId = IdRegistry::Instance().GetStringId(IdRegistry::Type::Block, blockId);
                     if (namespacedId.empty())
                         continue;
                     if (IsVanillaId(namespacedId))
                         continue;
-
-                    const int blockIndex = MakeBlockIndex(x, y, z);
                     if (namespacedId == kMissingBlockId)
                     {
-                        const auto it = previousEntries.find(blockIndex);
-                        if (it != previousEntries.end() && !it->second.empty() && it->second != kMissingBlockId)
-                            nextEntries[blockIndex] = it->second;
+                        const auto loadedIt = loadedEntries.find(blockIndex);
+                        if (loadedIt != loadedEntries.end() && !loadedIt->second.empty() && loadedIt->second != kMissingBlockId)
+                        {
+                            nextEntries[blockIndex] = loadedIt->second;
+                            continue;
+                        }
                         continue;
                     }
 
@@ -624,10 +899,14 @@ namespace WorldIdRemap
             }
         }
 
-        if (nextEntries.empty() && !hadExistingMap)
+        if (nextEntries.empty() && !hadLoadedMap)
             return;
         if (!WriteChunkNamespaceMap(storage->saveFile, path, nextEntries))
             return;
+        {
+            std::lock_guard<std::mutex> lock(s_chunkMetaMutex);
+            s_chunkNamespaceCache[cacheKey] = nextEntries;
+        }
 
         if (s_chunkSaveLogCount < 64)
         {
@@ -650,6 +929,8 @@ namespace WorldIdRemap
         const std::string namespacedId = ResolveNamespacedItemId(itemId);
         if (namespacedId.empty() || IsVanillaId(namespacedId))
             return;
+        const bool isBlockBacked = !IdRegistry::Instance().GetStringId(IdRegistry::Type::Block, itemId).empty() &&
+                                   IdRegistry::Instance().GetStringId(IdRegistry::Type::Item, itemId).empty();
 
         CompoundTagLayout* itemTag = EnsureItemTag(itemInstancePtr);
         if (!itemTag)
@@ -666,6 +947,7 @@ namespace WorldIdRemap
         const std::wstring namespacedWide(namespacedId.begin(), namespacedId.end());
         if (!PutCompoundString(itemTag, kNamespaceTagKey, namespacedWide))
             return;
+        (void)PutCompoundString(itemTag, kNamespaceKindTagKey, isBlockBacked ? L"block" : L"item");
     }
 
     void RemapItemInstanceFromTag(void* itemInstancePtr, void* compoundTagPtr)
@@ -685,9 +967,11 @@ namespace WorldIdRemap
         std::wstring namespacedWide;
         if (!TryGetCompoundString(itemTag, kNamespaceTagKey, &namespacedWide) || namespacedWide.empty())
             return;
+        std::wstring kindWide;
+        (void)TryGetCompoundString(itemTag, kNamespaceKindTagKey, &kindWide);
 
         const std::string namespacedId(namespacedWide.begin(), namespacedWide.end());
-        int numericId = ResolveNumericItemId(namespacedId, oldItemId);
+        int numericId = ResolveNumericItemId(namespacedId, oldItemId, kindWide);
         if (numericId >= 0)
             *reinterpret_cast<int*>(static_cast<char*>(itemInstancePtr) + kItemIdOffset) = numericId;
     }
diff --git a/WeaveLoaderRuntime/src/WorldIdRemap.h b/WeaveLoaderRuntime/src/WorldIdRemap.h
index 0bc8617..c87732a 100644
--- a/WeaveLoaderRuntime/src/WorldIdRemap.h
+++ b/WeaveLoaderRuntime/src/WorldIdRemap.h
@@ -5,7 +5,9 @@
 namespace WorldIdRemap
 {
     void SetTagNewTagSymbol(void* fnPtr);
+    void SetTileArraySymbol(void* tileArrayPtr);
     void SetLevelChunkTileSymbols(void* getTileFn, void* setTileFn, void* getPosFn, void* getHighestNonEmptyYFn);
+    void SetCompressedTileStorageSetSymbol(void* setFn);
     void EnsureMissingPlaceholders();
     int RemapChunkBlockIds(void* chunkStoragePtr, void* levelChunkPtr, int chunkX, int chunkZ);
     void SaveChunkBlockNamespaces(void* chunkStoragePtr, void* levelChunkPtr);