diff --git a/tests/repositories/epc/test_epc_roundtrip_corpus_gate.py b/tests/repositories/epc/test_epc_roundtrip_corpus_gate.py
index 700e94cf4..bbf8d2bd3 100644
--- a/tests/repositories/epc/test_epc_roundtrip_corpus_gate.py
+++ b/tests/repositories/epc/test_epc_roundtrip_corpus_gate.py
@@ -10,15 +10,7 @@ makes the two diverge, so a new persistence blind spot fails here immediately
 instead of being found by hand months later (it would have caught
 cylinder_heat_loss / room-in-roof / roof-windows / wall_u_value on day one).
 
-Known, documented exception — the `main_heating_fraction` DECIMAL cohort. The
-gov-EPC API lodges a two-main split as either a decimal fraction (`[0.8, 0.2]`)
-or a percent (`[80, 20]`); the `epc_main_heating_detail.main_heating_fraction`
-column is INTEGER, so a decimal pair truncates on save (`0.8 -> 1`). The real fix
-is #1666 (normalise to percent AT THE MAPPER, before save) which lands on the
-SAP-accuracy branch (#1672). Until #1672 is in `main`, those certs cannot
-round-trip; they are skipped here via a precise predicate (a non-integer lodged
-fraction). Once #1672 merges and this branch rebases, delete `_is_pre_1666_*`
-and the skip so the gate asserts a hard zero.
+Save+read+rollback per cert keeps the graph off disk (bounded, ~18s / 1000 certs).
 """
 
 from __future__ import annotations
@@ -30,7 +22,6 @@ from typing import Any
 from sqlalchemy import Engine
 from sqlmodel import Session
 
-from datatypes.epc.domain.epc_property_data import EpcPropertyData
 from datatypes.epc.domain.mapper import EpcPropertyDataMapper
 from domain.sap10_calculator.calculator import Sap10Calculator
 from repositories.epc.epc_postgres_repository import EpcPostgresRepository
@@ -42,17 +33,6 @@ _CORPUS = (
 _TOLERANCE = 1e-9
 
 
-def _is_pre_1666_decimal_fraction(epc: EpcPropertyData) -> bool:
-    """True when a lodged main_heating_fraction is non-integer, so the INTEGER
-    column truncates it on save. #1666 (mapper normalisation) removes this;
-    remove this predicate + skip once #1672 is in main."""
-    for main in epc.sap_heating.main_heating_details:
-        frac = main.main_heating_fraction
-        if frac is not None and float(frac) != int(frac):
-            return True
-    return False
-
-
 def test_round_trip_preserves_sap_over_the_corpus(db_engine: Engine) -> None:
     # Arrange
     calc = Sap10Calculator()
@@ -60,15 +40,11 @@ def test_round_trip_preserves_sap_over_the_corpus(db_engine: Engine) -> None:
 
     # Act — map -> save -> reload -> re-score every cert, collecting any drift.
     diverged: list[str] = []
-    skipped_pre_1666 = 0
     for line in lines:
         raw: dict[str, Any] = json.loads(line)
         epc = EpcPropertyDataMapper.from_api_response(raw)
         if epc is None:
             continue
-        if _is_pre_1666_decimal_fraction(epc):
-            skipped_pre_1666 += 1
-            continue
         try:
             direct = calc.calculate(epc).sap_score_continuous
         except Exception:
@@ -91,7 +67,6 @@ def test_round_trip_preserves_sap_over_the_corpus(db_engine: Engine) -> None:
 
     # Assert — no field the calculator reads is dropped on the DB round-trip.
     assert not diverged, (
-        f"{len(diverged)} cert(s) lost calculator-read fields on the DB round-trip "
-        f"({skipped_pre_1666} pre-#1666 decimal-fraction certs skipped):\n"
+        f"{len(diverged)} cert(s) lost calculator-read fields on the DB round-trip:\n"
         + "\n".join(diverged[:20])
     )