diff --git a/flake.nix b/flake.nix
index aeb2e905..1d303513 100644
--- a/flake.nix
+++ b/flake.nix
@@ -32,6 +32,9 @@
           cargo-machete
           protobuf
           oas3-gen
+          go
+          gopls
+          delve
         ];
 
         shellHook = ''
diff --git a/test-infra/compose/README.md b/test-infra/compose/README.md
index 95eb6380..c70750a3 100644
--- a/test-infra/compose/README.md
+++ b/test-infra/compose/README.md
@@ -116,7 +116,6 @@ Scenarios that intentionally degrade the cluster tune the gate via config, not t
 | Config knob | Effect | Used by |
 |-------------|--------|---------|
 | `AlertExcludeJobs` | exempt a node from the per-node rules (never from `Pluto Down`) | `1_of_4_down`, `1_of_3_down` |
-| `AlertWarnExcludeTopics` | extra warn-topic exclusions | `mixed_2_charon_2_pluto` (excludes `sched` until pluto serves infosync) |
 | `AlertDisableRules` | drop an entire rule | `1_of_3_down` (disables the error-rate gates — a downed round-1 leader makes every third proposer duty unrecoverable on the mock) |
 
 ## Versioning
diff --git a/test-infra/compose/config.go b/test-infra/compose/config.go
index d6f5915c..c41c782b 100644
--- a/test-infra/compose/config.go
+++ b/test-infra/compose/config.go
@@ -163,13 +163,6 @@ type Config struct {
 	// clean.
 	AlertExcludeJobs []string `json:"alert_exclude_jobs,omitempty"`
 
-	// AlertWarnExcludeTopics appends log topics to the Warn Log Rate
-	// exclusion list on top of the built-in charon mock noise (see
-	// writeAlertRules). Scenario-scoped escape hatch: e.g. mixed
-	// charon/pluto clusters exclude "sched" because charon's infosync warns
-	// each epoch until pluto serves /charon/priority/2.0.0 (#402B).
-	AlertWarnExcludeTopics []string `json:"alert_warn_exclude_topics,omitempty"`
-
 	// AlertDisableRules drops entire alert rules (by name, see
 	// alertRuleNames) from the generated rules. Last-resort scenario knob
 	// for cluster-wide degradation that per-job exclusion cannot express:
diff --git a/test-infra/compose/define.go b/test-infra/compose/define.go
index ad200a0e..0836687d 100644
--- a/test-infra/compose/define.go
+++ b/test-infra/compose/define.go
@@ -432,9 +432,8 @@ var alertRuleNames = map[string]bool{
 // writeAlertRules writes the prometheus alert rules evaluated by the smoke
 // tests. Rules are generated (not static) because the expressions depend on
 // config: scenarios that deliberately degrade a node exempt its job via
-// conf.AlertExcludeJobs, mixed-impl scenarios extend the warn-topic
-// exclusions via conf.AlertWarnExcludeTopics, and cluster-wide degradations
-// drop whole rules via conf.AlertDisableRules.
+// conf.AlertExcludeJobs, and cluster-wide degradations drop whole rules via
+// conf.AlertDisableRules.
 //
 // Charon's "Outstanding Duty Rate" rule (core_bcast_broadcast_total -
 // core_scheduler_duty_total > 50) is deliberately not ported: a node cannot
@@ -477,9 +476,9 @@ func writeAlertRules(dir string, conf Config) error {
 	//    every successful proposal epoch warns "Broadcasted block/attestation
 	//    never included on-chain" (the better the cluster works, the more it
 	//    warns).
-	// Both are mock artifacts, not node behavior; all other warn topics stay
-	// gated unless a scenario opts out via AlertWarnExcludeTopics.
-	warnTopics := strings.Join(append([]string{"vmock", "tracker"}, conf.AlertWarnExcludeTopics...), "|")
+	// Both are mock artifacts, not node behavior; every other warn topic stays
+	// gated.
+	const warnTopics = "vmock|tracker"
 
 	// The broadcast-liveness expression must fail when a node exposes NO
 	// core_bcast_broadcast_total series at all: the counter is created on
diff --git a/test-infra/compose/rules_internal_test.go b/test-infra/compose/rules_internal_test.go
index 08b4c263..99ef19a8 100644
--- a/test-infra/compose/rules_internal_test.go
+++ b/test-infra/compose/rules_internal_test.go
@@ -67,14 +67,11 @@ func TestWriteAlertRulesExcludesDegradedJobs(t *testing.T) {
 	require.Contains(t, content, "expr: up == 0")
 }
 
-// TestWriteAlertRulesWarnTopicExtension asserts scenario-scoped warn-topic
-// exclusions append to the built-in mock-noise list.
-func TestWriteAlertRulesWarnTopicExtension(t *testing.T) {
-	conf := NewDefaultConfig()
-	conf.AlertWarnExcludeTopics = []string{"sched"}
-
-	content := writeRules(t, conf)
-	require.Contains(t, content, `increase(app_log_warn_total{topic!~"vmock|tracker|sched"}[30s]) > 2`)
+// TestWriteAlertRulesWarnTopics asserts the Warn Log Rate gate excludes exactly
+// the two charon mock-noise topics.
+func TestWriteAlertRulesWarnTopics(t *testing.T) {
+	content := writeRules(t, NewDefaultConfig())
+	require.Contains(t, content, `increase(app_log_warn_total{topic!~"vmock|tracker"}[30s]) > 2`)
 }
 
 // TestWriteAlertRulesDropsOutstandingDuty pins the removal of charon's dead
diff --git a/test-infra/compose/smoke/smoke_test.go b/test-infra/compose/smoke/smoke_test.go
index 141b55b9..84ee48cb 100644
--- a/test-infra/compose/smoke/smoke_test.go
+++ b/test-infra/compose/smoke/smoke_test.go
@@ -236,12 +236,6 @@ func smokeScenarios() []smokeScenario {
 				}
 				// `pluto run` fails fast on --synthetic-block-proposals.
 				conf.SyntheticBlockProposals = false
-				// Charon triggers infosync (/charon/priority/2.0.0) every
-				// epoch; pluto does not serve the protocol yet (#402B), so
-				// charon nodes warn "P2P sending failing" under topic=sched
-				// twice per epoch. Exempt that topic in mixed clusters until
-				// the protocol lands; drop this with #402B.
-				conf.AlertWarnExcludeTopics = []string{"sched"}
 			},
 		},
 		{