diff --git a/tools/milestone0_baseline.py b/tools/milestone0_baseline.py
index 9598bb3..1709e4b 100644
--- a/tools/milestone0_baseline.py
+++ b/tools/milestone0_baseline.py
@@ -326,12 +326,13 @@ def _benchmark(root: Path, node_count: int, samples: int, cold_samples: int) ->
     def register() -> dict[str, object]:
         nonlocal registration_counter
         registration_counter += 1
+        proposal_node = _node_id(node_count - registration_counter)
         return store.register(
             f"benchmark-{registration_counter:03d}",
             [
                 {
                     "operation": "update",
-                    "node_id": target,
+                    "node_id": proposal_node,
                     "metadata": {
                         "summary": (
                             "Synthetic measurement node updated only inside a benchmark proposal."
@@ -342,7 +343,7 @@ def _benchmark(root: Path, node_count: int, samples: int, cold_samples: int) ->
             ],
         )
 
-    registration_samples = min(samples, 10)
+    registration_samples = min(samples, 10, node_count)
     operations["changeset_register"], registered = _measure(
         register,
         samples=registration_samples,