diff --git a/src/phase_z2_pipeline.py b/src/phase_z2_pipeline.py
index c72a3e8..12a13a2 100644
--- a/src/phase_z2_pipeline.py
+++ b/src/phase_z2_pipeline.py
@@ -25,6 +25,7 @@ MVP-1.5b spec :
 - mvp1.5b_test*  : 본 모듈, 원래 설계 라인 합류
 """
 
+import copy
 import hashlib
 import json
 import os
@@ -6112,15 +6113,31 @@ def _unit_for_t28_5_source_ids(
     return None
 
 
+# issue #16 — salvage 정책 차단 터미널 집합. 이 터미널에 도달했다는 것은
+# 자동 fit 레버(cross_zone/glue)가 소진되고 나머지(font/layout)는 정책
+# 잠금이라는 뜻 — popup escalation 이 유일한 무손실 자동 레버.
+_SALVAGE_POLICY_BLOCKED_TERMINALS = frozenset({
+    "layout_adjust_blocked_no_silent_layout_mutation",
+    "font_step_compression_blocked_no_font_shrink",
+})
+
+
 def _build_t28_5d_popup_targets(
     *,
     units: list[CompositionUnit],
     presentation_reselection: dict,
+    retry_trace: Optional[dict] = None,
 ) -> dict:
     """Select T28.5d popup targets from the T28.5c terminal trace.
 
     This is a deterministic bridge from T28.5c's abort/no-recovery signal
     onto the existing popup/details chain. It does not mutate units or HTML.
+
+    issue #16 — 두 번째 트리거 추가: salvage cascade 가 정책 차단 터미널로
+    소진됐는데 overflow 가 남은 zone (기존 트리거의
+    ``eligible_candidate_count == 0`` 조건은 이 분기에 미적용 — 그 후보들은
+    사용자 수동 경로일 뿐 자동 소비가 T19d 로 금지돼 있어, 후보가 있다는
+    이유로 무손실 popup 레버를 막으면 mdx04 처럼 영구 미발화가 됨).
     """
     layout_reselection = presentation_reselection.get("layout_reselection") or {}
     terminal = (
@@ -6129,36 +6146,119 @@ def _build_t28_5d_popup_targets(
         == "escalate_to_t28_5d_or_presentation_not_ready"
         and layout_reselection.get("allowed") is False
     )
+    salvage_exhausted = bool(
+        retry_trace
+        and retry_trace.get("salvage_attempted")
+        and not retry_trace.get("salvage_passed")
+        and retry_trace.get("salvage_terminal_action")
+        in _SALVAGE_POLICY_BLOCKED_TERMINALS
+    )
     targets: list[dict] = []
-    if terminal:
-        for zone in presentation_reselection.get("zones") or []:
-            overflow_px = int(zone.get("overflow_px") or 0)
-            overflow_x_px = int(zone.get("overflow_x_px") or 0)
-            if overflow_px <= 0 and overflow_x_px <= 0:
-                continue
-            if int(zone.get("eligible_candidate_count") or 0) != 0:
-                continue
-            source_ids = list(zone.get("source_section_ids") or [])
-            unit = _unit_for_t28_5_source_ids(units, source_ids)
-            if unit is None:
-                continue
-            targets.append({
-                "position": zone.get("position"),
-                "source_section_ids": source_ids,
-                "current_template_id": zone.get("current_template_id"),
-                "overflow_px": overflow_px,
-                "overflow_x_px": overflow_x_px,
-                "manual_geometry_applied": bool(zone.get("manual_geometry_applied")),
-            })
+    seen_positions: set = set()
+    for zone in presentation_reselection.get("zones") or []:
+        overflow_px = int(zone.get("overflow_px") or 0)
+        overflow_x_px = int(zone.get("overflow_x_px") or 0)
+        if overflow_px <= 0 and overflow_x_px <= 0:
+            continue
+        trigger_reason = None
+        if terminal and int(zone.get("eligible_candidate_count") or 0) == 0:
+            trigger_reason = "t28_5c_terminal_no_candidates"
+        elif salvage_exhausted:
+            trigger_reason = "salvage_exhausted_overflow_pressure"
+        if trigger_reason is None:
+            continue
+        source_ids = list(zone.get("source_section_ids") or [])
+        unit = _unit_for_t28_5_source_ids(units, source_ids)
+        if unit is None or zone.get("position") in seen_positions:
+            continue
+        seen_positions.add(zone.get("position"))
+        targets.append({
+            "position": zone.get("position"),
+            "source_section_ids": source_ids,
+            "current_template_id": zone.get("current_template_id"),
+            "overflow_px": overflow_px,
+            "overflow_x_px": overflow_x_px,
+            "manual_geometry_applied": bool(zone.get("manual_geometry_applied")),
+            "trigger_reason": trigger_reason,
+        })
     return {
         "triggered": bool(targets),
         "policy": "t28_5d_second_popup_pass_reuse_existing_chain",
         "terminal_next_step": presentation_reselection.get("next_step"),
+        "salvage_exhausted_trigger": salvage_exhausted,
         "target_count": len(targets),
         "targets": targets,
     }
 
 
+# issue #16 — popup escalation 시 zone 본문을 예산 내로 트리밍하는 헬퍼.
+# 기존 구조 결함: slide_base 는 partial_html 을 그대로 렌더하고 <details>
+# 를 덧붙이기만 함 (preview_text 는 렌더 경로 어디에서도 미소비) — popup
+# 이 높이를 전혀 줄이지 못해 escalation 이 항상 실패했음. 트리밍된 라인의
+# 전문은 popup body(raw_content 원문)에 보존 — 자세히보기 원칙, 텍스트
+# 무손실 (rendered_text_coverage 는 details 내부 텍스트도 집계).
+_POPUP_TRIM_LINE_PX = 18  # 13px font × 1.4lh 근사 (보수적)
+
+
+def _trim_slot_payload_for_overflow(
+    slot_payload: dict, overflow_px: int,
+) -> tuple[dict, int]:
+    """list-값 슬롯에서 overflow 해소에 필요한 만큼 라인을 제거 (긴 슬롯부터
+    round-robin, 슬롯당 최소 1라인 유지, label/title/_slot_count 무접촉).
+
+    두 형태를 지원:
+      - top-level list-of-str 슬롯 (예: ``pill_1_body``)
+      - list-of-dict 컬럼 내부의 list-of-str 값 (예: ``pillars[i].lines`` —
+        f13b three_parallel_requirements 계열)
+
+    Returns (새 payload, 제거 라인 수). 라인 경계에서만 자름 — 라인 내부
+    truncate 금지 (IMP-35 preview 철학과 동일).
+    """
+    if overflow_px <= 0 or not isinstance(slot_payload, dict):
+        return dict(slot_payload or {}), 0
+    need = int(overflow_px // _POPUP_TRIM_LINE_PX) + 1
+    new_payload = copy.deepcopy(slot_payload)
+
+    def _is_lines(v) -> bool:
+        # 라인 리스트 두 형태: list-of-str (verbatim builder 계열) 또는
+        # list-of-{text,...} line-object (f13b pillars.sections.text_lines 계열)
+        if not isinstance(v, list) or not v:
+            return False
+        if all(isinstance(x, str) for x in v):
+            return True
+        return all(
+            isinstance(x, dict) and isinstance(x.get("text"), str) for x in v
+        )
+
+    # trimmable pool: (container_dict, key) 참조를 재귀 수집 (깊이 제한 5)
+    pools: list[tuple[dict, str]] = []
+
+    def _collect(node, depth: int = 0) -> None:
+        if depth > 5:
+            return
+        if isinstance(node, dict):
+            for k, v in node.items():
+                if _is_lines(v):
+                    pools.append((node, k))
+                elif isinstance(v, (dict, list)):
+                    _collect(v, depth + 1)
+        elif isinstance(node, list):
+            for item in node:
+                if isinstance(item, (dict, list)):
+                    _collect(item, depth + 1)
+
+    _collect(new_payload)
+    trimmed = 0
+    while trimmed < need:
+        candidates = [(c, k) for c, k in pools if len(c[k]) > 1]
+        if not candidates:
+            break
+        container, key = max(candidates, key=lambda p: len(p[0][p[1]]))
+        container[key] = container[key][:-1]
+        trimmed += 1
+    return new_payload, trimmed
+
+
 def _t28_5d_popup_escalation_plan(target: dict) -> dict:
     return {
         "action": "details_popup_escalation",
@@ -6195,16 +6295,23 @@ def _attempt_t28_5d_popup_second_pass(
     postprocess_html=None,
     render_func=render_slide,
     overflow_check_func=run_overflow_check,
+    retry_trace: Optional[dict] = None,
 ) -> dict:
     """T28.5d: re-render final.html with existing popup/details payloads.
 
     The pass is intentionally after T28.5c because its trigger depends on
     presentation_fit + reselection trace. It is not marker-only: a candidate is
     rendered, measured, and promoted only if the visual check passes.
+
+    issue #16 — 두 가지 확장:
+      1. salvage 정책 차단 소진 시에도 트리거 (retry_trace 기반)
+      2. 대상 zone 의 본문 라인을 overflow 예산만큼 트리밍 — popup 이 실제로
+         높이를 줄이도록 (전문은 popup body 에 보존, 무손실)
     """
     target_plan = _build_t28_5d_popup_targets(
         units=units,
         presentation_reselection=presentation_reselection,
+        retry_trace=retry_trace,
     )
     result = {
         "triggered": target_plan["triggered"],
@@ -6244,30 +6351,81 @@ def _attempt_t28_5d_popup_second_pass(
         )
         zone.update(popup_payload)
         zone["t28_5d_popup_escalated"] = True
+        # issue #16 — 본문 라인 트리밍으로 높이 실감소 (전문은 popup body).
+        trimmed_payload, trimmed_lines = _trim_slot_payload_for_overflow(
+            zone.get("slot_payload") or {},
+            int(target.get("overflow_px") or 0),
+        )
+        if trimmed_lines:
+            zone["slot_payload"] = trimmed_payload
+            zone["popup_trimmed_lines"] = trimmed_lines
         applied_targets.append({
             **target,
             "popup_plan": plan,
+            "trimmed_lines": trimmed_lines,
         })
 
     if not applied_targets:
         result["failure_reason"] = "target_units_or_zones_not_found"
         return result
 
-    candidate_html = render_func(
-        slide_title,
-        slide_footer,
-        zones_candidate,
-        layout_preset,
-        layout_css,
-        gap_px=gap_px,
-    )
-    if postprocess_html is not None:
-        candidate_html = postprocess_html(candidate_html)
-
+    # issue #16 — 측정 피드백 트림 루프 (최대 3회). 라인당 px 추정치(18)가
+    # frame 마다 다를 수 있어, 후보 렌더의 측정 잔여 excess 로 추가 트림.
     candidate_path = run_dir / "t28_5d_popup_candidate.html"
-    candidate_path.write_text(candidate_html, encoding="utf-8")
-    candidate_overflow = overflow_check_func(candidate_path)
-    passed = bool(candidate_overflow.get("passed", False))
+    target_positions = {t.get("position") for t in applied_targets}
+    candidate_html = ""
+    candidate_overflow: dict = {}
+    passed = False
+    for _trim_round in range(3):
+        candidate_html = render_func(
+            slide_title,
+            slide_footer,
+            zones_candidate,
+            layout_preset,
+            layout_css,
+            gap_px=gap_px,
+        )
+        if postprocess_html is not None:
+            candidate_html = postprocess_html(candidate_html)
+        candidate_path.write_text(candidate_html, encoding="utf-8")
+        candidate_overflow = overflow_check_func(candidate_path)
+        passed = bool(candidate_overflow.get("passed", False))
+        if passed:
+            break
+        # 대상 zone 의 측정 잔여 excess 산출 → 추가 트림
+        extra_trimmed = 0
+        for oz in candidate_overflow.get("zones") or []:
+            pos = oz.get("position")
+            if pos not in target_positions:
+                continue
+            remaining = max(
+                int(round(float(oz.get("excess_y") or 0))),
+                max(
+                    [int(round(float(c.get("excess_y") or 0)))
+                     for c in oz.get("clipped_inner") or []] or [0]
+                ),
+            )
+            if remaining <= 0:
+                continue
+            zone = zone_by_position.get(pos)
+            if zone is None:
+                continue
+            more_payload, more = _trim_slot_payload_for_overflow(
+                zone.get("slot_payload") or {}, remaining,
+            )
+            if more:
+                zone["slot_payload"] = more_payload
+                zone["popup_trimmed_lines"] = (
+                    int(zone.get("popup_trimmed_lines") or 0) + more
+                )
+                for t in applied_targets:
+                    if t.get("position") == pos:
+                        t["trimmed_lines"] = (
+                            int(t.get("trimmed_lines") or 0) + more
+                        )
+                extra_trimmed += more
+        if extra_trimmed == 0:
+            break  # 더 줄일 여지 없음 — 정직 실패
     result.update({
         "attempted": True,
         "passed": passed,
@@ -11247,6 +11405,8 @@ def run_phase_z2_mvp1(
             override_slide_css=override_slide_css,
             mdx_source_text=mdx_source_text,
         ),
+        # issue #16 — salvage 정책 차단 소진 트리거용 (retry_trace 기반)
+        retry_trace=retry_trace,
     )
     slide_status["presentation_popup"] = t28_5d_popup_result
     if t28_5d_popup_result.get("promoted"):
diff --git a/tests/regression/fixtures/89a_pre_baseline_sha.json b/tests/regression/fixtures/89a_pre_baseline_sha.json
index 649b665..63b1b74 100644
--- a/tests/regression/fixtures/89a_pre_baseline_sha.json
+++ b/tests/regression/fixtures/89a_pre_baseline_sha.json
@@ -2,7 +2,7 @@
   "schema_version": 2,
   "axis": "IMP-89 89-a u4 — final.html SHA baseline captured via FULL run_phase_z2_mvp1 pipeline (flag OFF / default)",
   "description": "Frozen SHA-256 of `final.html` bytes (the artifact written to disk at src/phase_z2_pipeline.py:5994-5996) captured by running the full Phase Z pipeline end-to-end for each mdx 01-05 under PHASE_Z_B4_MAPPER_SOURCE=OFF. Under flag OFF the 89-a selector `_select_mapper_template_id(plan, T)` returns `T` verbatim, so the mapper input is byte-identical to the pre-89-a legacy call shape `map_mdx_to_slots(section, unit.frame_template_id)` — the rendered HTML and therefore the final.html SHA match the pre-89-a baseline. The u4 regression test runs the same pipeline shape under flag OFF and asserts SHA equality. Regenerate only when an upstream mapper/render/template delta is deliberately reviewed and accepted.",
-  "captured_at_utc": "2026-07-03T03:39:01Z",
+  "captured_at_utc": "2026-07-07T00:11:02Z",
   "renderer": {
     "entrypoint": "src.phase_z2_pipeline.run_phase_z2_mvp1",
     "write_site": "src/phase_z2_pipeline.py:5994-5996",
@@ -40,9 +40,9 @@
     "04.mdx": {
       "mdx_file": "04.mdx",
       "run_id": "89a_baseline_04",
-      "final_html_size_bytes": 40206,
-      "sha256": "8ba35bc6642b0e651cd46b9216070bd49052b016807611d9771fd630ca7a2613",
-      "pipeline_exit_code": 1
+      "final_html_size_bytes": 42265,
+      "sha256": "9c680c6f99c2e401f72edfdaf65e527e01263223eaaee70b9af75cb273ad3d3b",
+      "pipeline_exit_code": null
     },
     "05.mdx": {
       "mdx_file": "05.mdx",
diff --git a/tests/regression/fixtures/imp95_pre_baseline_sha.json b/tests/regression/fixtures/imp95_pre_baseline_sha.json
index 05addc9..35ea54a 100644
--- a/tests/regression/fixtures/imp95_pre_baseline_sha.json
+++ b/tests/regression/fixtures/imp95_pre_baseline_sha.json
@@ -2,7 +2,7 @@
   "schema_version": 1,
   "axis": "IMP-95 u8 — final.html SHA baseline captured via FULL run_phase_z2_mvp1 pipeline under PHASE_Z_B4_V4_EVIDENCE=OFF and PHASE_Z_B4_MAPPER_SOURCE=OFF (defaults)",
   "description": "Frozen SHA-256 of `final.html` bytes (production write site src/phase_z2_pipeline.py:5994-5996) for mdx 01/02/04/05 under PHASE_Z_B4_V4_EVIDENCE OFF. Under flag OFF, IMP-95 (u1~u7) is strictly no-op for final.html (planner branch falls through to legacy _select_frame at u3; u4/u5/u6 additive telemetry confined to placement_trace per the trace-only docstring at src/phase_z2_pipeline.py:86). The u8 regression test asserts SHA equality with these frozen values, so any future code change that drifts the flag-OFF render output produces a mismatch and breaks the test. mdx 03 is excluded per Stage 2 u8 scope (mdx 03 정비 LOCK). Regenerate only when an upstream delta is reviewed and accepted as the new pre-IMP-95 reference.",
-  "captured_at_utc": "2026-07-03T00:02:27Z",
+  "captured_at_utc": "2026-07-07T00:09:32Z",
   "renderer": {
     "entrypoint": "src.phase_z2_pipeline.run_phase_z2_mvp1",
     "write_site": "src/phase_z2_pipeline.py:5994-5996",
@@ -32,9 +32,9 @@
     "04.mdx": {
       "mdx_file": "04.mdx",
       "run_id": "imp95_baseline_04",
-      "final_html_size_bytes": 40206,
-      "sha256": "8ba35bc6642b0e651cd46b9216070bd49052b016807611d9771fd630ca7a2613",
-      "pipeline_exit_code": 1
+      "final_html_size_bytes": 42265,
+      "sha256": "9c680c6f99c2e401f72edfdaf65e527e01263223eaaee70b9af75cb273ad3d3b",
+      "pipeline_exit_code": null
     },
     "05.mdx": {
       "mdx_file": "05.mdx",
diff --git a/tests/test_phase_z2_issue16_popup_overflow_escalation.py b/tests/test_phase_z2_issue16_popup_overflow_escalation.py
new file mode 100644
index 0000000..701bd60
--- /dev/null
+++ b/tests/test_phase_z2_issue16_popup_overflow_escalation.py
@@ -0,0 +1,190 @@
+"""issue #16 — overflow 압력 기반 popup escalation 테스트 (MDX04 height-fit).
+
+배경 (실측):
+  - salvage cascade 실효 수단은 cross_zone/glue 2단뿐 (font_step=T28.5 차단,
+    layout_adjust=T19d 차단) — 소진 시 popup 이 유일한 무손실 자동 레버
+  - 기존 T28.5d 트리거는 eligible_candidate_count==0 요구 → 후보가 '존재만'
+    해도 영구 미발화 (mdx04: 후보 2개 있으나 자동 소비는 정책 금지)
+  - slide_base 는 partial 을 그대로 렌더 + <details> 추가 — preview_text 는
+    렌더 미소비라 popup 이 높이를 못 줄였음 → 라인 트리밍으로 실감소
+
+계약:
+  - 트리밍은 라인 경계에서만, 슬롯당 최소 1라인, label/title 무접촉
+  - 트리밍 전문은 popup body(raw_content 원문)에 보존 — 텍스트 무손실
+  - promote 는 candidate visual pass 시에만 (기존 정책 유지)
+"""
+from __future__ import annotations
+
+from types import SimpleNamespace
+
+from src.phase_z2_pipeline import (
+    _build_t28_5d_popup_targets,
+    _trim_slot_payload_for_overflow,
+)
+
+
+def _unit(ids):
+    return SimpleNamespace(source_section_ids=list(ids), raw_content="- 본문", title="t")
+
+
+def _reselection(zones, *, triggered=False, next_step="frame_or_layout_candidate_available",
+                 layout_allowed=True):
+    return {
+        "triggered": triggered,
+        "next_step": next_step,
+        "layout_reselection": {"allowed": layout_allowed},
+        "zones": zones,
+    }
+
+
+_BLOCKED_RT = {
+    "salvage_attempted": True,
+    "salvage_passed": False,
+    "salvage_terminal_action": "layout_adjust_blocked_no_silent_layout_mutation",
+}
+
+
+# ── 트리거 확장 ─────────────────────────────────────────────────────
+
+
+def test_salvage_exhausted_triggers_even_with_candidates():
+    """mdx04 재현: 후보 2개 존재 + salvage 정책 차단 소진 → 트리거."""
+    zones = [{
+        "position": "bottom", "source_section_ids": ["04-2"],
+        "current_template_id": "three_parallel_requirements",
+        "overflow_px": 70, "eligible_candidate_count": 2,
+    }]
+    plan = _build_t28_5d_popup_targets(
+        units=[_unit(["04-2"])],
+        presentation_reselection=_reselection(zones),
+        retry_trace=_BLOCKED_RT,
+    )
+    assert plan["triggered"] is True
+    assert plan["salvage_exhausted_trigger"] is True
+    assert plan["targets"][0]["trigger_reason"] == "salvage_exhausted_overflow_pressure"
+
+
+def test_font_step_block_terminal_also_triggers():
+    zones = [{"position": "top", "source_section_ids": ["05-1"],
+              "overflow_px": 30, "eligible_candidate_count": 1}]
+    rt = {**_BLOCKED_RT,
+          "salvage_terminal_action": "font_step_compression_blocked_no_font_shrink"}
+    plan = _build_t28_5d_popup_targets(
+        units=[_unit(["05-1"])],
+        presentation_reselection=_reselection(zones), retry_trace=rt,
+    )
+    assert plan["triggered"] is True
+
+
+def test_no_overflow_zone_not_targeted():
+    zones = [{"position": "top", "source_section_ids": ["01-1"],
+              "overflow_px": 0, "eligible_candidate_count": 0}]
+    plan = _build_t28_5d_popup_targets(
+        units=[_unit(["01-1"])],
+        presentation_reselection=_reselection(zones), retry_trace=_BLOCKED_RT,
+    )
+    assert plan["triggered"] is False
+
+
+def test_salvage_passed_does_not_trigger_new_branch():
+    zones = [{"position": "bottom", "source_section_ids": ["04-2"],
+              "overflow_px": 70, "eligible_candidate_count": 2}]
+    rt = {"salvage_attempted": True, "salvage_passed": True,
+          "salvage_terminal_action": None}
+    plan = _build_t28_5d_popup_targets(
+        units=[_unit(["04-2"])],
+        presentation_reselection=_reselection(zones), retry_trace=rt,
+    )
+    assert plan["triggered"] is False
+
+
+def test_legacy_terminal_trigger_preserved():
+    """기존 트리거(터미널 + 후보 0)는 retry_trace 없이도 동작 유지."""
+    zones = [{"position": "top", "source_section_ids": ["05-1"],
+              "overflow_px": 40, "eligible_candidate_count": 0}]
+    plan = _build_t28_5d_popup_targets(
+        units=[_unit(["05-1"])],
+        presentation_reselection=_reselection(
+            zones, triggered=True,
+            next_step="escalate_to_t28_5d_or_presentation_not_ready",
+            layout_allowed=False,
+        ),
+    )
+    assert plan["triggered"] is True
+    assert plan["targets"][0]["trigger_reason"] == "t28_5c_terminal_no_candidates"
+
+
+# ── 라인 트리밍 ─────────────────────────────────────────────────────
+
+
+def test_trim_removes_lines_from_longest_slot_first():
+    payload = {
+        "title": "제목",
+        "pillar_1_body": ["a", "b", "c", "d", "e"],
+        "pillar_2_body": ["x", "y"],
+        "pillar_1_label": "라벨",
+    }
+    new, n = _trim_slot_payload_for_overflow(payload, overflow_px=70)
+    # 70px → ceil(70/18)+... = 70//18+1 = 4 lines
+    assert n == 4
+    assert new["title"] == "제목"           # 비-list 무접촉
+    assert new["pillar_1_label"] == "라벨"
+    assert len(new["pillar_1_body"]) + len(new["pillar_2_body"]) == 7 - 4
+    assert len(new["pillar_2_body"]) >= 1   # 슬롯당 최소 1라인
+    # 원본 불변 (새 dict)
+    assert len(payload["pillar_1_body"]) == 5
+
+
+def test_trim_never_empties_a_slot():
+    payload = {"body": ["only-line"]}
+    new, n = _trim_slot_payload_for_overflow(payload, overflow_px=100)
+    assert n == 0
+    assert new["body"] == ["only-line"]
+
+
+def test_trim_zero_overflow_noop():
+    payload = {"body": ["a", "b"]}
+    new, n = _trim_slot_payload_for_overflow(payload, overflow_px=0)
+    assert n == 0 and new == payload
+
+
+def test_trim_stops_when_all_slots_at_minimum():
+    payload = {"a": ["1", "2"], "b": ["1", "2"]}
+    new, n = _trim_slot_payload_for_overflow(payload, overflow_px=500)
+    assert n == 2  # 각 슬롯 1라인까지만
+    assert new["a"] == ["1"] and new["b"] == ["1"]
+
+
+def test_trim_nested_list_of_dict_columns():
+    """중첩 1레벨 — pillars[i].lines 트리밍."""
+    payload = {"title": "t", "pillars": [
+        {"label": "A", "lines": ["1", "2", "3", "4"]},
+        {"label": "B", "lines": ["1", "2", "3", "4"]},
+    ]}
+    new, n = _trim_slot_payload_for_overflow(payload, overflow_px=70)
+    assert n == 4
+    assert new["pillars"][0]["label"] == "A"        # label 무접촉
+    assert len(new["pillars"][0]["lines"]) >= 1
+    total = sum(len(p["lines"]) for p in new["pillars"])
+    assert total == 8 - 4
+    assert len(payload["pillars"][0]["lines"]) == 4  # 원본 불변 (deepcopy)
+
+
+def test_trim_f13b_real_shape_text_line_objects():
+    """mdx04 실측 형태 — pillars[i].sections[j].text_lines[k]={'text':...}
+    3중 중첩 + line-object 리스트 (최초 두 구현이 못 찾던 케이스)."""
+    def lines(n):
+        return [{"text": f"내용 {i}", "indent": 0} for i in range(n)]
+    payload = {"title": "2. DX 추진의 실태", "pillars": [
+        {"label": "2.1", "sections": [{"heading": "", "text_lines": lines(9)}]},
+        {"label": "2.2", "sections": [{"heading": "", "text_lines": lines(9)}]},
+    ]}
+    new, n = _trim_slot_payload_for_overflow(payload, overflow_px=70)
+    assert n == 4  # 70//18+1
+    total = sum(
+        len(s["text_lines"]) for p in new["pillars"] for s in p["sections"]
+    )
+    assert total == 18 - 4
+    # 원본 불변 + label/heading 무접촉
+    assert len(payload["pillars"][0]["sections"][0]["text_lines"]) == 9
+    assert new["pillars"][0]["label"] == "2.1"