Fix LTX-2.3 checkpoint config metadata loading

_overlay/materialize.py

@@ -362,8 +362,9 @@ def materialize(
     )
 
     source_checkpoint = os.path.join(source_dir, "ltx-2.3-22b-dev.safetensors")
-    checkpoint_transformer_config = _load_checkpoint_config(source_checkpoint).get(
-        "transformer", {}
+    checkpoint_config = _load_checkpoint_config(source_checkpoint)
+    checkpoint_transformer_config = checkpoint_config.get(
+        "transformer", checkpoint_config
     )
 
     transformer_dir = os.path.join(output_dir, "transformer")