diff --git a/docs/roadmap/implementation.md b/docs/roadmap/implementation.md
index 0e5177e..81d0183 100644
--- a/docs/roadmap/implementation.md
+++ b/docs/roadmap/implementation.md
@@ -383,6 +383,12 @@ results also remain detached from metadata retained by the handle.
 
 ## Stage 14: Simplify Smoke Target And Public Report Detachment
 
+**Completed:** Smoke targets remain private through orchestration and public
+reports use the trusted outward projection; endpoint sanitization and credential
+redaction remain. Go 1.27.3 `go test ./internal/usecase . -run
+'Smoke|Diagnostic'` passed, including report isolation, cancellation, and
+diagnostic selection coverage.
+
 **Finding:** 5. **Files:** `internal/usecase/smoke_tester.go`,
 `smoke_diagnostics.go`, smoke conversion/ownership tests.
 
diff --git a/internal/usecase/smoke_tester.go b/internal/usecase/smoke_tester.go
index 83d462f..d20daa3 100644
--- a/internal/usecase/smoke_tester.go
+++ b/internal/usecase/smoke_tester.go
@@ -8,7 +8,6 @@ import (
 
 	"go.maximumdirect.net/promptkit/internal/domain"
 	"go.maximumdirect.net/promptkit/internal/generation"
-	"go.maximumdirect.net/promptkit/internal/jsonvalue"
 	"go.maximumdirect.net/promptkit/internal/llm"
 	"go.maximumdirect.net/promptkit/internal/observation"
 )
@@ -439,12 +438,8 @@ func httpExecutionFacts(evidence llm.HTTPExecutionEvidence) domain.SmokeTestFact
 }
 
 func smokeReportTarget(target domain.SmokeTestTarget) (domain.SmokeTestTarget, error) {
-	params, err := jsonvalue.CopyMap(target.EffectiveSettings.ExtraParams)
-	if err != nil {
-		return domain.SmokeTestTarget{}, fmt.Errorf("clone smoke-test target settings: %w", err)
-	}
-	target.EffectiveSettings.ExtraParams = params
 	target.EffectiveSettings.APIKey = ""
+	var err error
 	target.Endpoint, err = endpointWithoutUserInfo(target.Endpoint)
 	if err != nil {
 		return domain.SmokeTestTarget{}, fmt.Errorf("%w: invalid resolved diagnostic endpoint", ErrInvalidRequest)
diff --git a/internal/usecase/smoke_tester_test.go b/internal/usecase/smoke_tester_test.go
index c2765a7..9ded9e2 100644
--- a/internal/usecase/smoke_tester_test.go
+++ b/internal/usecase/smoke_tester_test.go
@@ -394,7 +394,7 @@ func (b cancelOnCloseSmokeBody) Close() error {
 	return b.ReadCloser.Close()
 }
 
-func TestSmokeReportTargetOwnsProviderValuesAndRedactsCredentials(t *testing.T) {
+func TestSmokeReportTargetRedactsCredentialsAndSanitizesEndpoints(t *testing.T) {
 	target := domain.SmokeTestTarget{
 		Endpoint: "https://user:password@example.invalid/key",
 		EffectiveSettings: domain.ExecutionTarget{
@@ -407,13 +407,8 @@ func TestSmokeReportTargetOwnsProviderValuesAndRedactsCredentials(t *testing.T)
 	if err != nil {
 		t.Fatal(err)
 	}
-	got.EffectiveSettings.ExtraParams["nested"].(map[string]any)["value"] = "changed"
-	if target.EffectiveSettings.ExtraParams["nested"].(map[string]any)["value"] != "original" ||
+	if got.EffectiveSettings.ExtraParams["nested"].(map[string]any)["value"] != "original" ||
 		got.EffectiveSettings.APIKey != "" || got.Endpoint != "https://example.invalid/key" || got.EffectiveSettings.Endpoint != "https://example.invalid/v1" {
-		t.Fatalf("report target not detached or redacted: %+v", got)
-	}
-	target.EffectiveSettings.ExtraParams = map[string]any{"invalid": func() {}}
-	if _, err := smokeReportTarget(target); err == nil {
-		t.Fatal("invalid provider values were accepted")
+		t.Fatalf("report target not redacted: %+v", got)
 	}
 }
diff --git a/smoke_conversion_internal_test.go b/smoke_conversion_internal_test.go
index 441d50b..52afac8 100644
--- a/smoke_conversion_internal_test.go
+++ b/smoke_conversion_internal_test.go
@@ -29,14 +29,8 @@ func TestSmokeReportConversionOwnsMutableValues(t *testing.T) {
 			Timing:     domain.SmokeTestTiming{RequestDuration: &duration},
 		}},
 	}
-	converted, err := fromDomainSmokeTestReport(source)
-	if err != nil {
-		t.Fatal(err)
-	}
-	other, err := fromDomainSmokeTestReport(source)
-	if err != nil {
-		t.Fatal(err)
-	}
+	converted := fromDomainSmokeTestReport(source)
+	other := fromDomainSmokeTestReport(source)
 	encoded, err := json.Marshal(converted)
 	if err != nil {
 		t.Fatal(err)
@@ -63,22 +57,8 @@ func TestSmokeReportConversionOwnsMutableValues(t *testing.T) {
 	if got := source.Target.EffectiveSettings.ExtraParams["nested"].([]any)[0].(map[string]any)["value"]; got != "original" {
 		t.Fatalf("converted report changed source provider parameters: %v", got)
 	}
-	later, err := fromDomainSmokeTestReport(source)
-	if err != nil {
-		t.Fatal(err)
-	}
+	later := fromDomainSmokeTestReport(source)
 	if !reflect.DeepEqual(other, later) {
 		t.Fatal("converted report mutation affected another result")
 	}
 }
-
-func TestSmokeReportConversionPreservesProviderMapCopyError(t *testing.T) {
-	report, err := fromDomainSmokeTestReport(domain.SmokeTestReport{
-		Target: domain.SmokeTestTarget{EffectiveSettings: domain.ExecutionTarget{
-			ExtraParams: map[string]any{"unsupported": func() {}},
-		}},
-	})
-	if err == nil || report != nil {
-		t.Fatalf("invalid provider data produced report=%+v, error=%v", report, err)
-	}
-}
diff --git a/smoke_diagnostics.go b/smoke_diagnostics.go
index 37c73e5..25a95a4 100644
--- a/smoke_diagnostics.go
+++ b/smoke_diagnostics.go
@@ -6,7 +6,6 @@ import (
 	"time"
 
 	"go.maximumdirect.net/promptkit/internal/domain"
-	"go.maximumdirect.net/promptkit/internal/jsonvalue"
 )
 
 // SmokeTestKind identifies one built-in diagnostic operation.
@@ -272,11 +271,7 @@ func (e *Engine) SmokeTest(ctx context.Context, req SmokeTestRequest) (*SmokeTes
 	if domainReport == nil {
 		return nil, mapPublicError(err)
 	}
-	report, conversionErr := fromDomainSmokeTestReport(*domainReport)
-	if conversionErr != nil {
-		return nil, fmt.Errorf("%w: failed to copy smoke-test report", ErrInvalidRequest)
-	}
-	return report, mapPublicError(err)
+	return fromDomainSmokeTestReport(*domainReport), mapPublicError(err)
 }
 
 func toDomainSmokeTestRequest(request SmokeTestRequest) (domain.SmokeTestRequest, error) {
@@ -295,11 +290,7 @@ func toDomainSmokeTestRequest(request SmokeTestRequest) (domain.SmokeTestRequest
 	}, nil
 }
 
-func fromDomainSmokeTestReport(report domain.SmokeTestReport) (*SmokeTestReport, error) {
-	extraParams, err := jsonvalue.CopyMap(report.Target.EffectiveSettings.ExtraParams)
-	if err != nil {
-		return nil, err
-	}
+func fromDomainSmokeTestReport(report domain.SmokeTestReport) *SmokeTestReport {
 	result := &SmokeTestReport{
 		Kind:       SmokeTestKind(report.Kind),
 		Supported:  report.Supported,
@@ -313,7 +304,7 @@ func fromDomainSmokeTestReport(report domain.SmokeTestReport) (*SmokeTestReport,
 			DefaultSourceBackendID: report.Target.DefaultSourceBackendID,
 			SelectionSource:        report.Target.SelectionSource,
 			Endpoint:               report.Target.Endpoint,
-			EffectiveSettings:      fromDomainExecutionTargetWithOwnedParams(report.Target.EffectiveSettings, extraParams),
+			EffectiveSettings:      fromDomainExecutionTarget(report.Target.EffectiveSettings),
 			SettingsPresence:       fromDomainExecutionTargetPresence(report.Target.SettingsPresence),
 		},
 		Facts:   fromDomainSmokeTestFacts(report.Facts),
@@ -336,7 +327,7 @@ func fromDomainSmokeTestReport(report domain.SmokeTestReport) (*SmokeTestReport,
 			}
 		}
 	}
-	return result, nil
+	return result
 }
 
 func fromDomainSmokeTestFacts(facts domain.SmokeTestFacts) SmokeTestFacts {