diff --git a/doc/en/audio.md b/doc/en/audio.md
index 9322583fd..cacd71074 100644
--- a/doc/en/audio.md
+++ b/doc/en/audio.md
@@ -60,7 +60,7 @@ Library **audio** contains available Audio API in Lua scripts.
 
 ```lua
 audio.play_stream(
-    -- audio file location
+    -- audio file location (without entry point, but with extension included)
     name: string, 
     -- audio source world position
     x: number, y: number, z: number,
@@ -79,7 +79,7 @@ Plays streaming audio from the specified file at the specified world position. R
 
 ```lua
 audio.play_stream_2d(
-    -- audio file location
+    -- audio file location (without entry point, but with extension included)
     name: string, 
     -- audio gain (0.0 - 1.0)
     volume: number
@@ -202,4 +202,4 @@ audio.count_speakers() -> integer
 
 -- get current number of playing streams
 audio.count_streams() -> integer
-```
\ No newline at end of file
+```
diff --git a/doc/en/world-generator.md b/doc/en/world-generator.md
index 2112bce21..b0ab265c9 100644
--- a/doc/en/world-generator.md
+++ b/doc/en/world-generator.md
@@ -52,6 +52,7 @@ The main properties described in the configuration file:
 - **biomes-bpd** - number of blocks per point of the biome selection parameter map. Default: 4.
 - **heights-bpd** - number of blocks per point of the height map. Default: 4.
 - **wide-structs-chunks-radius** - maximum radius for placing 'wide' structures, measured in chunks.
+- **heightmap-inputs** - an array of parameter map numbers that will be passed by the inputs table to the height map generation function.
 
 ## Global variables
 
diff --git a/doc/ru/audio.md b/doc/ru/audio.md
index b560b7392..1fce6c358 100644
--- a/doc/ru/audio.md
+++ b/doc/ru/audio.md
@@ -61,7 +61,7 @@
 
 ```lua
 audio.play_stream(
-    -- путь к аудио-файлу
+    -- путь к аудио-файлу (без точки входа, но с указанием расширения)
     name: string, 
     -- позиция источника аудио в мире
     x: number, y: number, z: number,
@@ -80,7 +80,7 @@ audio.play_stream(
 
 ```lua
 audio.play_stream_2d(
-    -- путь к аудио-файлу
+    -- путь к аудио-файлу (без точки входа, но с указанием расширения)
     name: string, 
     -- громкость аудио (от 0.0 до 1.0)
     volume: number
diff --git a/doc/ru/world-generator.md b/doc/ru/world-generator.md
index 1523f94ad..5c1c6e6e9 100644
--- a/doc/ru/world-generator.md
+++ b/doc/ru/world-generator.md
@@ -52,6 +52,7 @@
 - **biomes-bpd** - количество блоков на точку карты параметра выбора биомов. По-умолчанию: 4.
 - **heights-bpd** - количество блоков на точку карты высот. По-умолчанию: 4.
 - **wide-structs-chunks-radius** - масимальный радиус размещения 'широких' структур, измеряемый в чанках.
+- **heightmap-inputs** - массив номеров карт параметров, которые будут переданы таблицей inputs в функцию генерации карты высот.
 
 ## Глобальные переменные
 
diff --git a/res/scripts/stdmin.lua b/res/scripts/stdmin.lua
index 71fdbda2d..678983609 100644
--- a/res/scripts/stdmin.lua
+++ b/res/scripts/stdmin.lua
@@ -74,7 +74,7 @@ function table.deep_copy(t)
         end
     end
 
-    return copied
+    return setmetatable(copied, getmetatable(t))
 end
 
 function table.count_pairs(t)
diff --git a/src/content/ContentLoader.cpp b/src/content/ContentLoader.cpp
index 1e954a557..fee559e4f 100644
--- a/src/content/ContentLoader.cpp
+++ b/src/content/ContentLoader.cpp
@@ -220,11 +220,11 @@ void ContentLoader::loadBlock(
     }
 
     // block model
-    std::string modelTypeName;
+    std::string modelTypeName = to_string(def.model);
     root.at("model").get(modelTypeName);
     root.at("model-name").get(def.modelName);
     if (auto model = BlockModel_from(modelTypeName)) {
-        if (*model == BlockModel::custom) {
+        if (*model == BlockModel::custom && def.customModelRaw == nullptr) {
             if (root.has("model-primitives")) {
                 def.customModelRaw = root["model-primitives"];
             } else if (def.modelName.empty()) {
@@ -246,7 +246,7 @@ void ContentLoader::loadBlock(
     root.at("material").get(def.material);
 
     // rotation profile
-    std::string profile = "none";
+    std::string profile = def.rotations.name;
     root.at("rotation").get(profile);
 
     def.rotatable = profile != "none";
@@ -285,8 +285,6 @@ void ContentLoader::loadBlock(
         );
         aabb.b += aabb.a;
         def.hitboxes = {aabb};
-    } else {
-        def.hitboxes = {AABB()};
     }
 
     // block light emission [r, g, b] where r,g,b in range [0..15]
diff --git a/src/frontend/hud.cpp b/src/frontend/hud.cpp
index 1a2d83150..c07fe8171 100644
--- a/src/frontend/hud.cpp
+++ b/src/frontend/hud.cpp
@@ -47,6 +47,7 @@
 #include "window/Window.hpp"
 #include "world/Level.hpp"
 #include "world/World.hpp"
+#include "debug/Logger.hpp"
 
 #include <assert.h>
 #include <memory>
@@ -56,6 +57,8 @@
 
 using namespace gui;
 
+static debug::Logger logger("hud");
+
 bool Hud::showGeneratorMinimap = false;
 
 // implemented in debug_panel.cpp
@@ -486,7 +489,32 @@ void Hud::openPermanent(UiDocument* doc) {
     add(HudElement(hud_element_mode::permanent, doc, doc->getRoot(), false));
 }
 
+void Hud::dropExchangeSlot() {
+    auto slotView = std::dynamic_pointer_cast<SlotView>(
+        gui->get(SlotView::EXCHANGE_SLOT_NAME)
+    );
+    if (slotView == nullptr) {
+        return;
+    }
+    ItemStack& stack = slotView->getStack();
+    
+    auto indices = frontend.getLevel().content->getIndices();
+    if (auto invView = std::dynamic_pointer_cast<InventoryView>(blockUI)) {
+        invView->getInventory()->move(stack, indices);
+    }
+    if (stack.isEmpty()) {
+        return;
+    }
+    player->getInventory()->move(stack, indices);
+    if (!stack.isEmpty()) {
+        logger.warning() << "discard item [" << stack.getItemId() << ":"
+                         << stack.getCount();
+        stack.clear();
+    }
+}
+
 void Hud::closeInventory() {
+    dropExchangeSlot();
     gui->remove(SlotView::EXCHANGE_SLOT_NAME);
     exchangeSlot = nullptr;
     exchangeSlotInv = nullptr;
diff --git a/src/frontend/hud.hpp b/src/frontend/hud.hpp
index 5594664ac..ad834955a 100644
--- a/src/frontend/hud.hpp
+++ b/src/frontend/hud.hpp
@@ -128,6 +128,9 @@ class Hud : public util::ObjectsKeeper {
     void updateHotbarControl();
     void cleanup();
 
+    /// @brief Perform exchange slot removal when it's not empty.
+    void dropExchangeSlot();
+
     void showExchangeSlot();
     void updateWorldGenDebugVisualization();
 public:
diff --git a/src/voxels/Block.hpp b/src/voxels/Block.hpp
index e7fb182cf..557bf04cb 100644
--- a/src/voxels/Block.hpp
+++ b/src/voxels/Block.hpp
@@ -181,7 +181,7 @@ class Block {
     bool translucent = false;
 
     /// @brief Set of block physical hitboxes
-    std::vector<AABB> hitboxes;
+    std::vector<AABB> hitboxes {AABB()};
 
     /// @brief Set of available block rotations (coord-systems)
     BlockRotProfile rotations = BlockRotProfile::NONE;