diff --git a/utils/test_validate_reusable_sweep_artifacts.py b/utils/test_validate_reusable_sweep_artifacts.py
index e97516a71..69eb633cd 100644
--- a/utils/test_validate_reusable_sweep_artifacts.py
+++ b/utils/test_validate_reusable_sweep_artifacts.py
@@ -266,6 +266,40 @@ def test_multinode_agentic_identity_fields_match() -> None:
             assert identity({**default_row, field: 2}) != identity(default_row)
 
 
+def test_agentic_identity_freezes_nested_kv_offload_backend() -> None:
+    row = {
+        **agentic_result(),
+        "kv_offloading": "dram",
+        "kv_offload_backend": {
+            "name": "native",
+            "options": {"layers": ["cpu", "gpu"]},
+        },
+    }
+    row.pop("offloading")
+
+    identity = agentic_key(row)
+
+    assert isinstance(hash(identity), int)
+    assert identity == agentic_key(
+        {
+            **row,
+            "kv_offload_backend": {
+                "options": {"layers": ["cpu", "gpu"]},
+                "name": "native",
+            },
+        }
+    )
+    assert identity != agentic_key(
+        {
+            **row,
+            "kv_offload_backend": {
+                "name": "native",
+                "options": {"layers": ["cpu"]},
+            },
+        }
+    )
+
+
 def write_agentic_artifacts(
     root: Path,
     conc: int = 16,
@@ -519,6 +553,25 @@ def test_agentic_validation_rejects_duplicate_point_identity(
     assert "agentic point artifacts contain 1 duplicate row(s)" in errors
 
 
+def test_agentic_validation_handles_mapping_kv_offload_backend(
+    tmp_path: Path,
+) -> None:
+    row = {
+        **agentic_result(),
+        "kv_offloading": "dram",
+        "kv_offload_backend": {"name": "native"},
+    }
+    row.pop("offloading")
+    point_dir = tmp_path / "bmk_agentic_native_offload"
+    point_dir.mkdir()
+    (point_dir / "result.json").write_text(json.dumps([row, row]))
+    (tmp_path / "agentic_native_offload").mkdir()
+
+    errors = validate_agentic_artifacts(tmp_path)
+
+    assert "agentic point artifacts contain 1 duplicate row(s)" in errors
+
+
 def test_eval_only_main_does_not_require_benchmark_artifacts(
     tmp_path: Path,
     monkeypatch,
diff --git a/utils/validate_reusable_sweep_artifacts.py b/utils/validate_reusable_sweep_artifacts.py
index 7602768bd..0cfd1d266 100644
--- a/utils/validate_reusable_sweep_artifacts.py
+++ b/utils/validate_reusable_sweep_artifacts.py
@@ -110,13 +110,27 @@ def actual_benchmark_keys(artifacts_dir: Path) -> set[tuple[Any, ...]]:
     return set(actual_benchmark_key_rows(artifacts_dir))
 
 
+def freeze_identity_value(value: Any) -> Any:
+    """Convert nested JSON values into deterministic, hashable identities."""
+    if isinstance(value, dict):
+        return tuple(
+            sorted(
+                (key, freeze_identity_value(item))
+                for key, item in value.items()
+            )
+        )
+    if isinstance(value, (list, tuple)):
+        return tuple(freeze_identity_value(item) for item in value)
+    return value
+
+
 def agentic_key(row: dict[str, Any]) -> tuple[Any, ...]:
     """Build an agentic identity from one point result."""
     if "kv_offloading" in row:
         kv_offloading = row.get("kv_offloading") or "none"
         offload_key: Any = (
             kv_offloading,
-            (row.get("kv_offload_backend") or "")
+            freeze_identity_value(row.get("kv_offload_backend") or "")
             if kv_offloading != "none"
             else "",
         )