diff --git a/tests/test_application_coverage.py b/tests/test_application_coverage.py
index 798de2c..48888ca 100644
--- a/tests/test_application_coverage.py
+++ b/tests/test_application_coverage.py
@@ -245,6 +245,71 @@ class TestConversionService:
             log_messages = [msg for msg, _ in events.logs]
             assert any("Conversion failed" in msg for msg in log_messages)
 
+    def test_tts_context_applies_normalization_overrides(self):
+        """Service applies normalization_overrides from request to apostrophe config."""
+        from abogen.application.conversion_service import run_conversion
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            from abogen.application.conversion_config import PronunciationConfig
+
+            req = ConversionRequest(
+                direct_text="Hello",
+                voice="M1",
+                save_mode="custom_folder",
+                output_folder=Path(tmpdir),
+                pronunciation=PronunciationConfig(
+                    normalization_overrides={"normalization_numbers": False},
+                ),
+            )
+            events = FakeEvents()
+            pipeline = FakePipelineProvider()
+            resolver = FakeVoiceResolver()
+
+            result = run_conversion(req, events, pipeline, resolver)
+            assert result is not None
+
+    def test_tts_context_rejects_unconfigured_llm_mode(self):
+        """Service raises RuntimeError if LLM apostrophe mode is selected but unconfigured."""
+        from abogen.application.conversion_service import run_conversion
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            from abogen.application.conversion_config import PronunciationConfig
+
+            req = ConversionRequest(
+                direct_text="Hello",
+                voice="M1",
+                save_mode="custom_folder",
+                output_folder=Path(tmpdir),
+                pronunciation=PronunciationConfig(
+                    normalization_overrides={"normalization_apostrophe_mode": "llm"},
+                ),
+            )
+            events = FakeEvents()
+            pipeline = FakePipelineProvider()
+            resolver = FakeVoiceResolver()
+
+            with pytest.raises(RuntimeError, match="LLM.*apostrophe"):
+                run_conversion(req, events, pipeline, resolver)
+
+    def test_usage_counter_populated_in_result(self):
+        """usage_counter is created and accessible in result."""
+        from abogen.application.conversion_service import run_conversion
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            req = ConversionRequest(
+                direct_text="Hello",
+                voice="M1",
+                save_mode="custom_folder",
+                output_folder=Path(tmpdir),
+            )
+            events = FakeEvents()
+            pipeline = FakePipelineProvider()
+            resolver = FakeVoiceResolver()
+
+            result = run_conversion(req, events, pipeline, resolver)
+            assert hasattr(result, "usage_counter")
+            assert isinstance(result.usage_counter, dict)
+
 
 # ─── Tests for output_layout_service.py ─────────────────────────────
 
diff --git a/tests/test_conversion_planner.py b/tests/test_conversion_planner.py
index b9ae65d..4d52482 100644
--- a/tests/test_conversion_planner.py
+++ b/tests/test_conversion_planner.py
@@ -246,6 +246,30 @@ class TestWordSubstitution:
         assert len(plan.chapters) >= 1
         assert "cat" in plan.chapters[0].body_text
 
+    def test_chunks_assigned_to_correct_chapter(self):
+        """Chunks are grouped by chapter_index and only assigned to matching chapters."""
+        req = ConversionRequest(
+            direct_text="<<CHAPTER_MARKER:Ch1>>\nText A\n<<CHAPTER_MARKER:Ch2>>\nText B",
+            voice="M1",
+            chapter_chunk=ChapterChunkConfig(
+                chunks=[
+                    {"text": "Ch1 chunk", "chapter_index": 0},
+                    {"text": "Ch2 chunk", "chapter_index": 1},
+                ],
+            ),
+        )
+        plan = build_conversion_plan(req)
+
+        assert len(plan.chapters) == 2
+        # Ch1 should have only its chunk
+        ch1_texts = [s.text for s in plan.chapters[0].segments]
+        assert "Ch1 chunk" in ch1_texts
+        assert "Ch2 chunk" not in ch1_texts
+        # Ch2 should have only its chunk
+        ch2_texts = [s.text for s in plan.chapters[1].segments]
+        assert "Ch2 chunk" in ch2_texts
+        assert "Ch1 chunk" not in ch2_texts
+
     def test_no_substitution_when_disabled(self):
         """No substitution when word_substitution is None."""
         req = ConversionRequest(