The tracking statistics were actually too pessimistic
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 5069c76..931b1fc 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -498,6 +498,7 @@
 			_PyObject_GC_MAY_BE_TRACKED(ep[i].me_key))
 			return;
 	}
+	DECREASE_TRACK_COUNT
 	_PyObject_GC_UNTRACK(op);
 }