more changes

src/main/java/dev/ithundxr/railwaystweaks/mixin/MinecraftServerMixin.java

@@ -0,0 +1,17 @@
+package dev.ithundxr.railwaystweaks.mixin;
+
+import dev.ithundxr.railwaystweaks.mixinsupport.LevelLoadAppliers;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.progress.ChunkProgressListener;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin {
+    @Inject(method = "createLevels", at = @At("HEAD"))
+    private void railwaysTweaks$setupEntityTypeFilters(ChunkProgressListener listener, CallbackInfo ci) {
+        LevelLoadAppliers.init();
+    }
+}

src/main/java/dev/ithundxr/railwaystweaks/mixinsupport/LevelLoadAppliers.java

@@ -0,0 +1,14 @@
+package dev.ithundxr.railwaystweaks.mixinsupport;
+
+public class LevelLoadAppliers {
+    private static boolean ran = false;
+
+    public static void init() {
+        if (ran) {
+            return;
+        }
+        ran = true;
+
+        FlatBlockstateArray.apply();
+    }
+}

src/main/resources/railwaystweaks.mixins.json

@@ -7,6 +7,7 @@
   "mixins": [
     "DedicatedServerMixin",
     "LevelChunkSectionMixin",
+    "MinecraftServerMixin",
     "ServerPlayerMixin",
     "ServerStatusPacketListenerImplMixin",
     "compat.appleskin.SyncHandlerMixin",