diff --git a/core/src/main/java/org/geysermc/geyser/registry/BlockRegistries.java b/core/src/main/java/org/geysermc/geyser/registry/BlockRegistries.java
index ad07740a7..21a792fc5 100644
--- a/core/src/main/java/org/geysermc/geyser/registry/BlockRegistries.java
+++ b/core/src/main/java/org/geysermc/geyser/registry/BlockRegistries.java
@@ -116,12 +116,7 @@ public class BlockRegistries {
     /**
      * A registry which stores Custom Block Data for extended collision boxes and the Java IDs of blocks that will have said extended collision boxes placed above them.
      */
-    public static final SimpleMappedRegistry<CustomBlockData, Set<Integer>> EXTENDED_COLLISION_BOXES_DATA = SimpleMappedRegistry.create(RegistryLoaders.empty(Object2ObjectOpenHashMap::new));
-
-    /**
-     * A registry which stores Java IDs of blocks that will have a custom collision block placed above them and the Bedrock ID of said collision block.
-     */
-    public static final SimpleMappedRegistry<Integer, Integer> EXTENDED_COLLISION_BOXES = SimpleMappedRegistry.create(RegistryLoaders.empty(Object2ObjectOpenHashMap::new));
+    public static final SimpleMappedRegistry<CustomBlockData, Set<Integer>> EXTENDED_COLLISION_BOXES = SimpleMappedRegistry.create(RegistryLoaders.empty(Object2ObjectOpenHashMap::new));
 
     /**
      * A registry which stores skin texture hashes to custom skull blocks.
diff --git a/core/src/main/java/org/geysermc/geyser/registry/populator/BlockRegistryPopulator.java b/core/src/main/java/org/geysermc/geyser/registry/populator/BlockRegistryPopulator.java
index da2572d72..52baa9a9e 100644
--- a/core/src/main/java/org/geysermc/geyser/registry/populator/BlockRegistryPopulator.java
+++ b/core/src/main/java/org/geysermc/geyser/registry/populator/BlockRegistryPopulator.java
@@ -33,6 +33,8 @@ import com.nukkitx.protocol.bedrock.data.BlockPropertyData;
 import com.nukkitx.protocol.bedrock.v544.Bedrock_v544;
 import com.nukkitx.protocol.bedrock.v560.Bedrock_v560;
 import com.nukkitx.protocol.bedrock.v567.Bedrock_v567;
+import it.unimi.dsi.fastutil.ints.Int2IntMap;
+import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
 import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
 import it.unimi.dsi.fastutil.ints.IntSet;
 import it.unimi.dsi.fastutil.objects.Object2IntMap;
@@ -140,16 +142,17 @@ public final class BlockRegistryPopulator {
             }
 
             Object2IntMap<CustomBlockState> customBlockStateIds = Object2IntMaps.emptyMap();
+            Int2IntMap extendedCollisionBoxes = new Int2IntOpenHashMap();
             if (BlockRegistries.CUSTOM_BLOCKS.get().length != 0) {
                 customBlockStateIds = new Object2IntOpenHashMap<>(customExtBlockStates.size());
-                Map<Integer, Integer> extendedCollisionBoxes = new HashMap<>();
+                //Map<Integer, Integer> extendedCollisionBoxes = new HashMap<>();
                 for (int i = 0; i < customExtBlockStates.size(); i++) {
                     NbtMap tag = customBlockStates.get(i);
                     CustomBlockState blockState = customExtBlockStates.get(i);
                     int bedrockRuntimeId = blockStateOrderedMap.getOrDefault(tag, -1);
                     customBlockStateIds.put(blockState, bedrockRuntimeId);
 
-                    Set<Integer> extendedCollisionjavaIds = BlockRegistries.EXTENDED_COLLISION_BOXES_DATA.getOrDefault(blockState.block(), null);
+                    Set<Integer> extendedCollisionjavaIds = BlockRegistries.EXTENDED_COLLISION_BOXES.getOrDefault(blockState.block(), null);
                     if (extendedCollisionjavaIds != null) {
                         for (int javaId : extendedCollisionjavaIds) {
                             extendedCollisionBoxes.put(javaId, bedrockRuntimeId);
@@ -157,8 +160,6 @@ public final class BlockRegistryPopulator {
                     }
                 }
 
-                BlockRegistries.EXTENDED_COLLISION_BOXES.set(extendedCollisionBoxes);
-
                 remappedVanillaIds = new int[vanillaBlockStates.size()];
                 for (int i = 0; i < vanillaBlockStates.size(); i++) {
                     remappedVanillaIds[i] = blockStateOrderedMap.getOrDefault(vanillaBlockStates.get(i), -1);
@@ -273,6 +274,7 @@ public final class BlockRegistryPopulator {
                     .remappedVanillaIds(remappedVanillaIds)
                     .blockProperties(customBlockProperties)
                     .customBlockStateIds(customBlockStateIds)
+                    .extendedCollisionBoxes(extendedCollisionBoxes)
                     .build());
         }
 
diff --git a/core/src/main/java/org/geysermc/geyser/registry/populator/CustomBlockRegistryPopulator.java b/core/src/main/java/org/geysermc/geyser/registry/populator/CustomBlockRegistryPopulator.java
index 805513368..3bc5e2a83 100644
--- a/core/src/main/java/org/geysermc/geyser/registry/populator/CustomBlockRegistryPopulator.java
+++ b/core/src/main/java/org/geysermc/geyser/registry/populator/CustomBlockRegistryPopulator.java
@@ -8,7 +8,6 @@ import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
 import org.checkerframework.checker.nullness.qual.NonNull;
-import org.geysermc.geyser.Constants;
 import org.geysermc.geyser.GeyserImpl;
 import org.geysermc.geyser.api.block.custom.CustomBlockData;
 import org.geysermc.geyser.api.block.custom.CustomBlockPermutation;
@@ -131,7 +130,7 @@ public class CustomBlockRegistryPopulator {
         BlockRegistries.CUSTOM_BLOCK_ITEM_OVERRIDES.set(customBlockItemOverrides);
         GeyserImpl.getInstance().getLogger().info("Registered " + customBlockItemOverrides.size() + " custom block item overrides.");
 
-        BlockRegistries.EXTENDED_COLLISION_BOXES_DATA.set(extendedCollisionBoxes);
+        BlockRegistries.EXTENDED_COLLISION_BOXES.set(extendedCollisionBoxes);
         GeyserImpl.getInstance().getLogger().info("Registered " + extendedCollisionBoxes.size() + " custom block extended collision boxes.");
     }
 
diff --git a/core/src/main/java/org/geysermc/geyser/registry/type/BlockMappings.java b/core/src/main/java/org/geysermc/geyser/registry/type/BlockMappings.java
index 7c3cc0c79..668ec2002 100644
--- a/core/src/main/java/org/geysermc/geyser/registry/type/BlockMappings.java
+++ b/core/src/main/java/org/geysermc/geyser/registry/type/BlockMappings.java
@@ -28,6 +28,7 @@ package org.geysermc.geyser.registry.type;
 import com.nukkitx.nbt.NbtList;
 import com.nukkitx.nbt.NbtMap;
 import com.nukkitx.protocol.bedrock.data.BlockPropertyData;
+import it.unimi.dsi.fastutil.ints.Int2IntMap;
 import it.unimi.dsi.fastutil.ints.IntSet;
 import it.unimi.dsi.fastutil.objects.Object2IntMap;
 import lombok.Builder;
@@ -61,6 +62,7 @@ public class BlockMappings {
 
     List<BlockPropertyData> blockProperties;
     Object2IntMap<CustomBlockState> customBlockStateIds;
+    Int2IntMap extendedCollisionBoxes;
 
     public int getBedrockBlockId(int state) {
         if (state >= this.javaToBedrockBlocks.length) {
diff --git a/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaLevelChunkWithLightTranslator.java b/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaLevelChunkWithLightTranslator.java
index ecc5e9a5c..5bf48549b 100644
--- a/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaLevelChunkWithLightTranslator.java
+++ b/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaLevelChunkWithLightTranslator.java
@@ -69,7 +69,6 @@ import org.geysermc.geyser.util.BlockEntityUtils;
 import org.geysermc.geyser.util.ChunkUtils;
 
 import java.io.IOException;
-import java.util.Arrays;
 import java.util.BitSet;
 import java.util.List;
 import java.util.Map;
@@ -111,10 +110,13 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
         try {
             ByteBuf in = Unpooled.wrappedBuffer(packet.getChunkData());
             int runningSectionExtendedCollisions[] = new int[BlockStorage.SIZE];
+            boolean extendedCollisionNextSection = false;
             for (int sectionY = 0; sectionY < chunkSize; sectionY++) {
                 ChunkSection javaSection = session.getCodecHelper().readChunkSection(in, biomeGlobalPalette);
                 javaChunks[sectionY] = javaSection.getChunkData();
                 javaBiomes[sectionY] = javaSection.getBiomeData();
+                boolean extendedCollision = extendedCollisionNextSection;
+                boolean thisExtendedCollisionNextSection = false;
 
                 int bedrockSectionY = sectionY + (yOffset - (bedrockDimension.minY() >> 4));
                 if (bedrockSectionY < 0 || maxBedrockSectionY < bedrockSectionY) {
@@ -144,17 +146,19 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
                         }
 
                         // Extended collision blocks
-                        switch (yzx) {
-                            case 0 -> Arrays.fill(runningSectionExtendedCollisions, 256, 4095, 0);
-                            case 256 -> Arrays.fill(runningSectionExtendedCollisions, 0, 256, 0);
-                        }
-                        if (javaId == BlockStateValues.JAVA_AIR_ID && runningSectionExtendedCollisions[yzx] != 0) {
-                            section.getBlockStorageArray()[0].setFullBlock(xzy, runningSectionExtendedCollisions[yzx]);
-                            continue;
-                        }
-                        int aboveBedrockExtendedCollisionId = BlockRegistries.EXTENDED_COLLISION_BOXES.getOrDefault(javaId, -1);
-                        if (aboveBedrockExtendedCollisionId != -1) {
-                            runningSectionExtendedCollisions[((yzx & 0x0ff) | (((yzx >> 8) + ((xzy & 0xF) < 15 ? 1 : -15)) << 8))] = aboveBedrockExtendedCollisionId;
+                        if (!session.getBlockMappings().getExtendedCollisionBoxes().isEmpty()) {
+                            if (javaId == BlockStateValues.JAVA_AIR_ID && runningSectionExtendedCollisions[yzx] != 0) {
+                                section.getBlockStorageArray()[0].setFullBlock(xzy, runningSectionExtendedCollisions[yzx]);
+                                runningSectionExtendedCollisions[yzx] = 0;
+                                continue;
+                            }
+                            int aboveBedrockExtendedCollisionId = session.getBlockMappings().getExtendedCollisionBoxes().getOrDefault(javaId, -1);
+                            if (aboveBedrockExtendedCollisionId != -1) {
+                                runningSectionExtendedCollisions[((yzx & 0x0ff) | (((yzx >> 8) + ((xzy & 0xF) < 15 ? 1 : -15)) << 8))] = aboveBedrockExtendedCollisionId;
+                                if ((xzy & 0xF) == 15) {
+                                    thisExtendedCollisionNextSection = true;
+                                }
+                            }
                         }
 
                         // Check if block is piston or flower to see if we'll need to create additional block entities, as they're only block entities in Bedrock
@@ -185,7 +189,8 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
                     continue;
                 }
 
-                IntList bedrockPalette = new IntArrayList(javaPalette.size());
+                IntList bedrockPalette = new IntArrayList();
+                int airPaletteId = -1;
                 waterloggedPaletteIds.clear();
                 bedrockOnlyBlockEntityIds.clear();
 
@@ -198,6 +203,17 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
                         waterloggedPaletteIds.set(i);
                     }
 
+                    if (javaId == BlockStateValues.JAVA_AIR_ID) {
+                        airPaletteId = i;
+                    }
+
+                    if (!session.getBlockMappings().getExtendedCollisionBoxes().isEmpty() && !extendedCollision) {
+                        int aboveBedrockExtendedCollisionId = session.getBlockMappings().getExtendedCollisionBoxes().getOrDefault(javaId, -1);
+                        if (aboveBedrockExtendedCollisionId != -1) {
+                            extendedCollision = true;
+                        }
+                    }
+
                     // Check if block is piston, flower or cauldron to see if we'll need to create additional block entities, as they're only block entities in Bedrock
                     if (BlockStateValues.getFlowerPotValues().containsKey(javaId) || BlockStateValues.getPistonValues().containsKey(javaId) || BlockStateValues.isNonWaterCauldron(javaId)) {
                         bedrockOnlyBlockEntityIds.set(i);
@@ -224,31 +240,17 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
                 BlockStorage[] layers;
 
                 // Convert data array from YZX to XZY coordinate order
-                if (waterloggedPaletteIds.isEmpty()) {
+                if (waterloggedPaletteIds.isEmpty() && !extendedCollision) {
                     // No blocks are waterlogged, simply convert coordinate order
                     // This could probably be optimized further...
                     for (int yzx = 0; yzx < BlockStorage.SIZE; yzx++) {
                         int paletteId = javaData.get(yzx);
                         int xzy = indexYZXtoXZY(yzx);
                         bedrockData.set(xzy, paletteId);
-
-                        switch (yzx) {
-                            case 0 -> Arrays.fill(runningSectionExtendedCollisions, 256, 4095, 0);
-                            case 256 -> Arrays.fill(runningSectionExtendedCollisions, 0, 256, 0);
-                        }
-                        int javaId = javaPalette.idToState(paletteId);
-                        if (javaId == BlockStateValues.JAVA_AIR_ID && runningSectionExtendedCollisions[yzx] != 0) {
-                            bedrockData.set(xzy, layer0.idFor(runningSectionExtendedCollisions[yzx]));
-                            continue;
-                        }
-                        int aboveBedrockExtendedCollisionId = BlockRegistries.EXTENDED_COLLISION_BOXES.getOrDefault(javaId, -1);
-                        if (aboveBedrockExtendedCollisionId != -1) {
-                            runningSectionExtendedCollisions[((yzx & 0x0ff) | (((yzx >> 8) + ((xzy & 0xF) < 15 ? 1 : -15)) << 8))] = aboveBedrockExtendedCollisionId;
-                        }
                     }
 
                     layers = new BlockStorage[]{ layer0 };
-                } else {
+                } else if (!waterloggedPaletteIds.isEmpty() && !extendedCollision) {
                     // The section contains waterlogged blocks, we need to convert coordinate order AND generate a V1 block storage for
                     // layer 1 with palette ID 1 indicating water
                     int[] layer1Data = new int[BlockStorage.SIZE >> 5];
@@ -260,19 +262,57 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
                         if (waterloggedPaletteIds.get(paletteId)) {
                             layer1Data[xzy >> 5] |= 1 << (xzy & 0x1F);
                         }
+                    }
+                    
+                    // V1 palette
+                    IntList layer1Palette = IntList.of(
+                            session.getBlockMappings().getBedrockAirId(), // Air - see BlockStorage's constructor for more information
+                            session.getBlockMappings().getBedrockWaterId());
 
-                        switch (yzx) {
-                            case 0 -> Arrays.fill(runningSectionExtendedCollisions, 256, 4095, 0);
-                            case 256 -> Arrays.fill(runningSectionExtendedCollisions, 0, 256, 0);
-                        }
-                        int javaId = javaPalette.idToState(paletteId);
-                        if (javaId == BlockStateValues.JAVA_AIR_ID && runningSectionExtendedCollisions[yzx] != 0) {
+                    layers = new BlockStorage[]{ layer0, new BlockStorage(BitArrayVersion.V1.createArray(BlockStorage.SIZE, layer1Data), layer1Palette) };
+                } else if (waterloggedPaletteIds.isEmpty() && extendedCollision) {
+                    for (int yzx = 0; yzx < BlockStorage.SIZE; yzx++) {
+                        int paletteId = javaData.get(yzx);
+                        int xzy = indexYZXtoXZY(yzx);
+                        bedrockData.set(xzy, paletteId);
+
+                        if (paletteId == airPaletteId && runningSectionExtendedCollisions[yzx] != 0) {
                             bedrockData.set(xzy, layer0.idFor(runningSectionExtendedCollisions[yzx]));
+                            runningSectionExtendedCollisions[yzx] = 0;
                             continue;
                         }
-                        int aboveBedrockExtendedCollisionId = BlockRegistries.EXTENDED_COLLISION_BOXES.getOrDefault(javaId, -1);
+                        int aboveBedrockExtendedCollisionId = session.getBlockMappings().getExtendedCollisionBoxes().getOrDefault(javaPalette.idToState(paletteId), -1);
                         if (aboveBedrockExtendedCollisionId != -1) {
                             runningSectionExtendedCollisions[((yzx & 0x0ff) | (((yzx >> 8) + ((xzy & 0xF) < 15 ? 1 : -15)) << 8))] = aboveBedrockExtendedCollisionId;
+                            if ((xzy & 0xF) == 15) {
+                                thisExtendedCollisionNextSection = true;
+                            }
+                        }
+                    }
+
+                    layers = new BlockStorage[]{ layer0 };
+                } else {
+                    int[] layer1Data = new int[BlockStorage.SIZE >> 5];
+                    for (int yzx = 0; yzx < BlockStorage.SIZE; yzx++) {
+                        int paletteId = javaData.get(yzx);
+                        int xzy = indexYZXtoXZY(yzx);
+                        bedrockData.set(xzy, paletteId);
+
+                        if (waterloggedPaletteIds.get(paletteId)) {
+                            layer1Data[xzy >> 5] |= 1 << (xzy & 0x1F);
+                        }
+
+                        if (paletteId == airPaletteId && runningSectionExtendedCollisions[yzx] != 0) {
+                            bedrockData.set(xzy, layer0.idFor(runningSectionExtendedCollisions[yzx]));
+                            runningSectionExtendedCollisions[yzx] = 0;
+                            continue;
+                        }
+                        int aboveBedrockExtendedCollisionId = session.getBlockMappings().getExtendedCollisionBoxes().getOrDefault(javaPalette.idToState(paletteId), -1);
+                        if (aboveBedrockExtendedCollisionId != -1) {
+                            runningSectionExtendedCollisions[((yzx & 0x0ff) | (((yzx >> 8) + ((xzy & 0xF) < 15 ? 1 : -15)) << 8))] = aboveBedrockExtendedCollisionId;
+                            if ((xzy & 0xF) == 15) {
+                                thisExtendedCollisionNextSection = true;
+                            }
                         }
                     }
 
@@ -285,6 +325,7 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
                 }
 
                 sections[bedrockSectionY] = new GeyserChunkSection(layers);
+                extendedCollisionNextSection = thisExtendedCollisionNextSection;
             }
 
             session.getChunkCache().addToCache(packet.getX(), packet.getZ(), javaChunks);
diff --git a/core/src/main/java/org/geysermc/geyser/util/ChunkUtils.java b/core/src/main/java/org/geysermc/geyser/util/ChunkUtils.java
index 90ee2adfe..3c30b1aaa 100644
--- a/core/src/main/java/org/geysermc/geyser/util/ChunkUtils.java
+++ b/core/src/main/java/org/geysermc/geyser/util/ChunkUtils.java
@@ -143,22 +143,24 @@ public class ChunkUtils {
         }
 
         // Extended collision boxes for custom blocks
-        int aboveBedrockExtendedCollisionId = BlockRegistries.EXTENDED_COLLISION_BOXES.getOrDefault(blockState, -1);
-        int aboveBlock = session.getChunkCache().getBlockAt(position.getX(), position.getY() + 1, position.getZ());
-        if (aboveBedrockExtendedCollisionId != -1) {
-            UpdateBlockPacket updateBlockPacket = new UpdateBlockPacket();
-            updateBlockPacket.setDataLayer(0);
-            updateBlockPacket.setBlockPosition(position.add(0, 1, 0));
-            updateBlockPacket.setRuntimeId(aboveBedrockExtendedCollisionId);
-            updateBlockPacket.getFlags().add(UpdateBlockPacket.Flag.NETWORK);
-            session.sendUpstreamPacket(updateBlockPacket);
-        } else if (aboveBlock == BlockStateValues.JAVA_AIR_ID) {
-            UpdateBlockPacket updateBlockPacket = new UpdateBlockPacket();
-            updateBlockPacket.setDataLayer(0);
-            updateBlockPacket.setBlockPosition(position.add(0, 1, 0));
-            updateBlockPacket.setRuntimeId(session.getBlockMappings().getBedrockAirId());
-            updateBlockPacket.getFlags().add(UpdateBlockPacket.Flag.NETWORK);
-            session.sendUpstreamPacket(updateBlockPacket);
+        if (!session.getBlockMappings().getExtendedCollisionBoxes().isEmpty()) {
+            int aboveBedrockExtendedCollisionId = session.getBlockMappings().getExtendedCollisionBoxes().getOrDefault(blockState, -1);
+            int aboveBlock = session.getGeyser().getWorldManager().getBlockAt(session, position.getX(), position.getY() + 1, position.getZ());
+            if (aboveBedrockExtendedCollisionId != -1) {
+                UpdateBlockPacket updateBlockPacket = new UpdateBlockPacket();
+                updateBlockPacket.setDataLayer(0);
+                updateBlockPacket.setBlockPosition(position.add(0, 1, 0));
+                updateBlockPacket.setRuntimeId(aboveBedrockExtendedCollisionId);
+                updateBlockPacket.getFlags().add(UpdateBlockPacket.Flag.NETWORK);
+                session.sendUpstreamPacket(updateBlockPacket);
+            } else if (aboveBlock == BlockStateValues.JAVA_AIR_ID) {
+                UpdateBlockPacket updateBlockPacket = new UpdateBlockPacket();
+                updateBlockPacket.setDataLayer(0);
+                updateBlockPacket.setBlockPosition(position.add(0, 1, 0));
+                updateBlockPacket.setRuntimeId(session.getBlockMappings().getBedrockAirId());
+                updateBlockPacket.getFlags().add(UpdateBlockPacket.Flag.NETWORK);
+                session.sendUpstreamPacket(updateBlockPacket);
+            }
         }
 
         // Prevent moving_piston from being placed