Added a way to skip block checking for game modes.

https://github.com/BentoBoxWorld/BentoBox/issues/1694

src/main/java/world/bentobox/bentobox/api/configuration/WorldSettings.java

@@ -555,4 +555,17 @@ public interface WorldSettings extends ConfigObject {
     default boolean isMakeEndPortals() {
         return false;
     }
+    
+    /**
+     * Check for blocks when searching for a new island. This is a safety net check that does a look
+     * around the new island location (3x3x3 block check). If any non-air or non-water blocks are found
+     * then the island is marked as being used. It is mainly for migration handling from worlds that
+     * do not register island properly. It is incompatible with CaveBlock or other gamemodes that will
+     * have blocks there.
+     * @return true if a check for blocks should happen
+     * @since 1.16.0
+     */
+    default boolean isCheckForBlocks() {
+        return true;
+    }
 }

src/main/java/world/bentobox/bentobox/managers/IslandWorldManager.java

@@ -726,6 +726,20 @@ public class IslandWorldManager {
         return gameModes.containsKey(world) && gameModes.get(world).getWorldSettings().isUseOwnGenerator();
     }
     
+    /**
+     * Check for blocks when searching for a new island. This is a safety net check that does a look
+     * around the new island location (3x3x3 block check). If any non-air or non-water blocks are found
+     * then the island is marked as being used. It is mainly for migration handling from worlds that
+     * do not register island properly. It is incompatible with CaveBlock or other gamemodes that will
+     * have blocks there.
+     * @param world - world
+     * @return true if a check for blocks should happen
+     * @since 1.16.0
+     */
+    public boolean isCheckForBlocks(@NonNull World world) {
+        return gameModes.containsKey(world) && gameModes.get(world).getWorldSettings().isCheckForBlocks();
+    }
+
     /**
      * Return banned commands for visitors
      * @return the visitorbannedcommands

src/main/java/world/bentobox/bentobox/managers/island/DefaultNewIslandLocationStrategy.java

@@ -100,8 +100,11 @@ public class DefaultNewIslandLocationStrategy implements NewIslandLocationStrate
             return Result.FREE;
         }
         // Block check
-        if (!plugin.getIWM().isUseOwnGenerator(world) && Arrays.asList(BlockFace.values()).stream().anyMatch(bf -> 
+        if (plugin.getIWM().isCheckForBlocks(world) 
-        !location.getBlock().getRelative(bf).isEmpty() && !location.getBlock().getRelative(bf).getType().equals(Material.WATER))) {
+                && !plugin.getIWM().isUseOwnGenerator(world) 
+                && Arrays.asList(BlockFace.values()).stream().anyMatch(bf -> 
+                !location.getBlock().getRelative(bf).isEmpty() 
+                && !location.getBlock().getRelative(bf).getType().equals(Material.WATER))) {
             // Block found
             plugin.getIslands().createIsland(location);
             return Result.BLOCKS_IN_AREA;