diff --git a/rs/moq-mux/benches/catalog.rs b/rs/moq-mux/benches/catalog.rs
index d354f486719..279c1d51f5f 100644
--- a/rs/moq-mux/benches/catalog.rs
+++ b/rs/moq-mux/benches/catalog.rs
@@ -3,11 +3,12 @@
 //! Every track's jitter rises 1 ms per frame for [`RISES`] frames inside one rate window, then one
 //! more frame lands after the window. Each catalog a subscriber receives makes a player update its
 //! subscription on every track, so the work fans out as `publishes x tracks x subscribers`. The
-//! routine asserts the rate limit holds that to two publishes (the leading and trailing edge)
+//! hang case asserts the rate limit holds that to two publishes (the leading and trailing edge)
 //! whatever the shape; without it the count would be `RISES x tracks x subscribers`.
 //!
-//! The MSF reference case publishes renditions in distinct sibling namespaces and converts them
-//! back for every subscriber, exercising namespace resolution over both fanout axes.
+//! The MSF reference case declares renditions in distinct sibling namespaces and converts the
+//! initial catalog back for every subscriber. MSF keeps the estimates it first declared, so this
+//! case asserts that measured rises cause no further catalogs or subscription updates.
 //! The rate window runs on tokio's paused clock, so the counts are deterministic.
 //!
 //! The teardown case drops a reserved importer whose declared tracks never got a config, as at the
@@ -82,7 +83,7 @@ impl Fanout {
 			waiter: kio::Waiter::noop(),
 		};
 		// The initial track set is configuration, not estimate traffic.
-		fanout.receive();
+		assert_eq!(fanout.receive(), (1, fanout.tracks.len() * subscribers));
 		fanout
 	}
 
@@ -125,7 +126,7 @@ impl Fanout {
 		(publishes, updates)
 	}
 
-	async fn run(mut self) {
+	async fn run(mut self, expected: usize) {
 		let (mut publishes, mut updates) = (0, 0);
 		let mut tally = |(p, u): (usize, usize)| {
 			publishes += p;
@@ -142,7 +143,7 @@ impl Fanout {
 		let shape = self.tracks.len() * self.subscribers.len();
 		assert_eq!(
 			(publishes, updates),
-			(2, 2 * shape),
+			(expected, expected * shape),
 			"estimate churn regression with {} tracks x {} subscribers",
 			self.tracks.len(),
 			self.subscribers.len()
@@ -158,6 +159,7 @@ fn bench_estimate_fanout(c: &mut Criterion) {
 		.unwrap();
 	let mut group = c.benchmark_group("catalog_estimate_fanout");
 	for (mode, references) in [("hang", false), ("msf_references", true)] {
+		let expected = if references { 0 } else { 2 };
 		for tracks in TRACKS {
 			for subscribers in SUBSCRIBERS {
 				group.throughput(Throughput::Elements(RISES * tracks as u64));
@@ -167,7 +169,7 @@ fn bench_estimate_fanout(c: &mut Criterion) {
 					|b, &(tracks, subscribers)| {
 						b.iter_batched(
 							|| runtime.block_on(Fanout::new(tracks, subscribers, references)),
-							|fanout| runtime.block_on(fanout.run()),
+							|fanout| runtime.block_on(fanout.run(expected)),
 							BatchSize::SmallInput,
 						);
 					},