diff --git a/tests/mars_stream/test_domains.cpp b/tests/mars_stream/test_domains.cpp
index aa9806e..3531ac5 100644
--- a/tests/mars_stream/test_domains.cpp
+++ b/tests/mars_stream/test_domains.cpp
@@ -124,7 +124,17 @@ int main() {
     // 2026-09-09, 22 saves: 724 fields observed, 490 vary, 234 do not.  Nearly a
     // third of the format we call "99.99% typed" has been seen holding exactly
     // one value.  `tscr` was one of those 234 until a one-turn tech moved it.
-    const size_t kVaryingBaseline = 490;
+    //
+    // 2026-09-09, 43 saves (lane DW): 755 fields observed, 538 vary, 217 do not.
+    // The corpus doubled and the census grew by 31 fields, of which 19 are this
+    // lane's newly typed bodies -- the `usp`/`usc` pair of a name-generator record,
+    // the twelve of a `Sprj` back-engineering project, and the five of a stored
+    // formation point.  Only two of those 19 have ever been seen to move
+    // (`FTPShID`, `FTPDesID`), which is exactly why the count of CONSTANTS rose
+    // faster than the count of varying fields: typing a body honestly adds far
+    // more unexercised fields than exercised ones, and this census is the place
+    // that stays visible.
+    const size_t kVaryingBaseline = 538;
     CHECK(varying >= kVaryingBaseline);
 
     std::printf("test_domains: %s (%zu save(s), %d failure(s))\n", fails ? "FAILED" : "ok", saves.size(), fails);
diff --git a/tests/mars_stream/test_save.cpp b/tests/mars_stream/test_save.cpp
index e257514..6e70fda 100644
--- a/tests/mars_stream/test_save.cpp
+++ b/tests/mars_stream/test_save.cpp
@@ -142,6 +142,16 @@ static void check_save(const std::string& path, const char* dump_dir) {
         // With TurnCommands_v5 typed, the only items left carried as Nodes are the
         // two of the MT19937 block, which is deliberately opaque.
         CHECK(pct >= 99.99);
+        // The percentage is the WEAKER half of this ratchet and cannot be raised
+        // usefully: it is 2/items, so tightening it would fail on a *small* save
+        // that types perfectly and pass a big one that carries a new opaque body.
+        // The strong form is the item count itself.  2026-09-09, 43 saves: the only
+        // opaque items in any save are the MT19937 block's two (`RNG`), so the
+        // ratchet is that exact set.  A newly-carried body breaks this line first,
+        // and it breaks it on the save that has the body, not on the smallest one.
+        // Raise it -- by typing the body -- the way rule 27 says; never widen it.
+        CHECK(cov.opaque == 2);
+        CHECK(cov.opaque_by_tag.size() == 1 && cov.opaque_by_tag.count("RNG") == 1);
     }
 
     // --- round trips ------------------------------------------------------------------