diff --git a/crates/bft-json-crdt/Cargo.toml b/crates/bft-json-crdt/Cargo.toml
index f006b563..c74aa39d 100644
--- a/crates/bft-json-crdt/Cargo.toml
+++ b/crates/bft-json-crdt/Cargo.toml
@@ -6,8 +6,14 @@ edition = "2021"
 [lib]
 crate-type = ["lib"]
 
+# The logging-* features print multi-KB debug dumps on every CRDT op — and
+# they execute inside the global CRDT state mutex in the server, so a stalled
+# stdout write while holding that lock can pin every tokio worker and freeze
+# the whole process (bug 1170). They are development tools: opt in explicitly
+# with `--features bft-json-crdt/logging-list` when debugging CRDT internals.
+# Never enable them in a production build.
 [features]
-default = ["bft", "logging-list", "logging-json"]
+default = ["bft"]
 logging-list = ["logging-base"]
 logging-json = ["logging-base"]
 logging-base = []
diff --git a/server/src/crdt_state/state/tests.rs b/server/src/crdt_state/state/tests.rs
index b55d5a12..3e989240 100644
--- a/server/src/crdt_state/state/tests.rs
+++ b/server/src/crdt_state/state/tests.rs
@@ -330,23 +330,27 @@ fn persist_tx_send_success_emits_no_warn() {
     })
     .into();
 
-    let before_warns = crate::log_buffer::global()
-        .get_recent_entries(
-            1000,
-            Some("[crdt_persist]"),
-            Some(&crate::log_buffer::LogLevel::Warn),
-        )
-        .len();
+    // Count only warns mentioning THIS test's story: the log buffer is
+    // process-global, so parallel tests emit their own [crdt_persist] warns
+    // and a bare count races (flaked when the logging-list feature removal
+    // changed test timing).
+    let count_own_warns = || {
+        crate::log_buffer::global()
+            .get_recent_entries(
+                1000,
+                Some("[crdt_persist]"),
+                Some(&crate::log_buffer::LogLevel::Warn),
+            )
+            .iter()
+            .filter(|e| e.message.contains("676_story_happy_path"))
+            .count()
+    };
+
+    let before_warns = count_own_warns();
 
     apply_and_persist(&mut state, |s| s.crdt.doc.items.insert(ROOT_ID, item_json));
 
-    let after_warns = crate::log_buffer::global()
-        .get_recent_entries(
-            1000,
-            Some("[crdt_persist]"),
-            Some(&crate::log_buffer::LogLevel::Warn),
-        )
-        .len();
+    let after_warns = count_own_warns();
 
     assert_eq!(
         after_warns, before_warns,