diff --git a/test/test_model.py b/test/test_model.py
index e636f0e..b577819 100644
--- a/test/test_model.py
+++ b/test/test_model.py
@@ -2481,6 +2481,99 @@ class MainTests(unittest.TestCase):
         self.assertFalse(hasattr(b2.F1, "xb"))
         self.assertFalse(hasattr(c2.F1, "xc"))
 
+    def test_dict_field_override_with_nested_containers(self):
+        class App(dm.BaseAppliance):
+            data: dict[str, list[int]] = {"numbers": [1, 2]}
+
+        app = App(data={"numbers": [9, 8]})
+        # Dict must be frozen, lists inside must become tuples
+        self.assertEqual(type(app.data).__name__, "frozendict")
+        self.assertIsInstance(app.data["numbers"], tuple)
+        self.assertEqual(app.data["numbers"], (9, 8))
+
+        # Wrong type inside list should raise
+        with self.assertRaises(dm.InvalidFieldValue):
+            App(data={"numbers": [1, "oops"]})
+
+    def test_feature_dict_override_with_nested_containers(self):
+        class App(dm.BaseAppliance):
+            class F1(dm.BaseFeature):
+                values: list[int] = [1, 2]
+
+        app = App(F1={"values": [5, 6]})
+        self.assertEqual(app.F1.values, (5, 6))  # deepfreeze → tuple
+
+        # Invalid type in list should fail
+        with self.assertRaises(dm.InvalidFieldValue):
+            App(F1={"values": [1, "oops"]})
+
+    def test_initializer_modifies_nested_containers(self):
+        class App(dm.BaseAppliance):
+            data: dict[str, list[int]] = {"nums": [1]}
+
+            @classmethod
+            def __initializer(cls):
+                # Append into nested list
+                cls.data["nums"].append(2)
+
+        app = App()
+        self.assertEqual(app.data["nums"], (1, 2))  # frozen tuple after init
+
+    def test_feature_dict_override_with_unknown_key(self):
+        class App(dm.BaseAppliance):
+            class F1(dm.BaseFeature):
+                a: int = 1
+
+        # Dict override with unknown field 'zzz'
+        with self.assertRaises(dm.InvalidFieldValue):
+            App(F1={"zzz": 42})
+
+    def test_schema_isolation_across_multiple_feature_overrides(self):
+        class App(dm.BaseAppliance):
+            class F1(dm.BaseFeature):
+                a: int = 1
+
+        class F1a(App.F1):
+            a = 10
+
+        class F1b(App.F1):
+            a = 20
+
+        app1 = App(F1=F1a)
+        self.assertIsInstance(app1.F1, F1a)
+        self.assertEqual(app1.F1.a, 10)
+
+        app2 = App(F1=F1b)
+        self.assertIsInstance(app2.F1, F1b)
+        self.assertEqual(app2.F1.a, 20)
+
+        # Original appliance schema must not be polluted
+        app3 = App()
+        self.assertIsInstance(app3.F1, App.F1)
+        self.assertEqual(app3.F1.a, 1)
+
+    def test_feature_inheritance_with_annotated_fields(self):
+        from typing_extensions import Annotated
+
+        class App(dm.BaseAppliance):
+            class F1(dm.BaseFeature):
+                a: Annotated[int, dm.DABFieldInfo(doc="field a")] = 1
+
+        # ✅ Subclass override must inherit from parent F1
+        class F1Ex(App.F1):
+            b: str = "ok"
+
+        app = App(F1=F1Ex)
+        self.assertIsInstance(app.F1, F1Ex)
+        self.assertEqual((app.F1.a, app.F1.b), (1, "ok"))
+
+        # ❌ Wrong: fresh BaseFeature under same name
+        with self.assertRaises(dm.InvalidFeatureInheritance):
+
+            class Bad(App):
+                class F1(dm.BaseFeature):
+                    fail: str = "oops"
+
 
 # ---------- main ----------