This does something idk.

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitBlockRegistry.java

@@ -19,6 +19,7 @@
 
 package com.sk89q.worldedit.bukkit;
 
+import com.sk89q.worldedit.world.block.BlockTypes;
 import com.sk89q.worldedit.world.registry.BlockMaterial;
 import com.sk89q.worldedit.registry.state.Property;
 import com.sk89q.worldedit.world.block.BlockState;
@@ -34,8 +35,8 @@ import java.util.OptionalInt;
 import javax.annotation.Nullable;
 
 public class BukkitBlockRegistry extends BundledBlockRegistry {
-
     private Map<Material, BukkitBlockMaterial> materialMap = new EnumMap<>(Material.class);
+    private BlockState[] statesById = new BlockState[2 << 14];
 
     @Nullable
     @Override
@@ -58,10 +59,32 @@ public class BukkitBlockRegistry extends BundledBlockRegistry {
 
     @Override
     public OptionalInt getInternalBlockStateId(BlockState state) {
-        if (WorldEditPlugin.getInstance().getBukkitImplAdapter() != null) {
+        if (state.getBlockType() == BlockTypes.AIR) {
-            return WorldEditPlugin.getInstance().getBukkitImplAdapter().getInternalBlockStateId(state);
+            statesById[0] = state;
+            return OptionalInt.of(0);
         }
-        return super.getInternalBlockStateId(state);
+        final OptionalInt id;
+        if (WorldEditPlugin.getInstance().getBukkitImplAdapter() != null) {
+            id = WorldEditPlugin.getInstance().getBukkitImplAdapter().getInternalBlockStateId(state);
+        } else {
+            id = super.getInternalBlockStateId(state);
+        }
+        if (id.isPresent()) {
+            final int idx = id.getAsInt();
+            if (statesById.length <= idx) {
+                BlockState[] newArr = new BlockState[statesById.length * 2];
+                System.arraycopy(statesById, 0, newArr, 0, statesById.length);
+                statesById = newArr;
+            }
+            statesById[idx] = state;
+        }
+        return id;
+    }
+
+    @Nullable
+    @Override
+    public BlockState getBlockStateByInternalId(int id) {
+        return id >= statesById.length ? null : statesById[id];
     }
 
     public static class BukkitBlockMaterial extends PassthroughBlockMaterial {

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitWorld.java

@@ -415,8 +415,18 @@ public class BukkitWorld extends AbstractWorld {
 
     @Override
     public com.sk89q.worldedit.world.block.BlockState getBlock(BlockVector3 position) {
-        Block bukkitBlock = getWorld().getBlockAt(position.getBlockX(), position.getBlockY(), position.getBlockZ());
+        BukkitImplAdapter adapter = WorldEditPlugin.getInstance().getBukkitImplAdapter();
-        return BukkitAdapter.adapt(bukkitBlock.getBlockData());
+        if (adapter != null) {
+            try {
+                return adapter.getBlock(BukkitAdapter.adapt(getWorld(), position)).toImmutableState();
+            } catch (Exception e) {
+                Block bukkitBlock = getWorld().getBlockAt(position.getBlockX(), position.getBlockY(), position.getBlockZ());
+                return BukkitAdapter.adapt(bukkitBlock.getBlockData());
+            }
+        } else {
+            Block bukkitBlock = getWorld().getBlockAt(position.getBlockX(), position.getBlockY(), position.getBlockZ());
+            return BukkitAdapter.adapt(bukkitBlock.getBlockData());
+        }
     }
 
     @Override

worldedit-core/src/main/java/com/sk89q/worldedit/regions/CuboidRegion.java

@@ -345,9 +345,9 @@ public class CuboidRegion extends AbstractRegion implements FlatRegion {
                 BlockVector3 answer = BlockVector3.at(nextX, nextY, nextZ);
                 if (++nextX > max.getBlockX()) {
                     nextX = min.getBlockX();
-                    if (++nextY > max.getBlockY()) {
+                    if (++nextZ > max.getBlockZ()) {
-                        nextY = min.getBlockY();
+                        nextZ = min.getBlockZ();
-                        if (++nextZ > max.getBlockZ()) {
+                        if (++nextY > max.getBlockY()) {
                             nextX = Integer.MIN_VALUE;
                         }
                     }

worldedit-core/src/main/java/com/sk89q/worldedit/world/block/BlockState.java

@@ -46,7 +46,7 @@ import java.util.Set;
  */
 @SuppressWarnings("unchecked")
 public class BlockState implements BlockStateHolder<BlockState> {
-    
+
     static {
         BlockStateIdAccess.setBlockStateStateId(x -> x.internalId);
     }
@@ -86,13 +86,14 @@ public class BlockState implements BlockStateHolder<BlockState> {
             List<List<Object>> valueLists = Lists.cartesianProduct(separatedValues);
             for (List<Object> valueList : valueLists) {
                 Map<Property<?>, Object> valueMap = Maps.newTreeMap(Comparator.comparing(Property::getName));
-                BlockState stateMaker = new BlockState(blockType).initializeId(registry);
+                BlockState stateMaker = new BlockState(blockType);
                 for (int i = 0; i < valueList.size(); i++) {
                     Property<?> property = properties.get(i);
                     Object value = valueList.get(i);
                     valueMap.put(property, value);
                     stateMaker.setState(property, value);
                 }
+                stateMaker.initializeId(registry);
                 stateMap.put(valueMap, stateMaker);
             }
         }

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/BlockRegistry.java

@@ -67,4 +67,11 @@ public interface BlockRegistry {
      */
     OptionalInt getInternalBlockStateId(BlockState state);
 
+    /**
+     * Retrieve a block state by its internal ID, if possible.
+     *
+     * @param id The internal ID
+     * @return the block state, if available
+     */
+    BlockState getBlockStateByInternalId(int id);
 }

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/BundledBlockRegistry.java

@@ -59,4 +59,9 @@ public class BundledBlockRegistry implements BlockRegistry {
         return OptionalInt.empty();
     }
 
+    @Override
+    public BlockState getBlockStateByInternalId(int id) {
+        return null;
+    }
+
 }