diff --git a/.gitignore b/.gitignore
index 339aaa0d..c727841c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -172,3 +172,8 @@ pyrightconfig.json
 # End of https://www.toptal.com/developers/gitignore/api/python,visualstudiocode
 *.err
 *.out
+
+# iterate2 local run artifacts
+experiment_logs/
+iterate_study.db
+*.db
diff --git a/setup.cfg b/setup.cfg
index d266050d..3185af3e 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -27,3 +27,7 @@ exclude =
 [flake8]
 max-line-length = 80
 ignore = E203, E501, W503
+# C3 code-generation templates are string.Template files containing
+# ${placeholder} substitutions; they are not valid standalone Python and
+# must not be linted (they trip E999 SyntaxError).
+extend-exclude = src/claimed/c3/templates
diff --git a/src/claimed/c3/operator_utils.py b/src/claimed/c3/operator_utils.py
index 5f524872..93049680 100644
--- a/src/claimed/c3/operator_utils.py
+++ b/src/claimed/c3/operator_utils.py
@@ -1,6 +1,9 @@
 import contextlib
 import logging
 import os
+import re
+import subprocess
+import time
 
 # converts string in form [cos|s3]://access_key_id:secret_access_key@endpoint/bucket/path to
 # access_key_id, secret_access_key, endpoint, path - path includes bucket name
diff --git a/src/claimed/components/examples/fibonacci.py b/src/claimed/components/examples/fibonacci.py
index 377c34ff..50240730 100644
--- a/src/claimed/components/examples/fibonacci.py
+++ b/src/claimed/components/examples/fibonacci.py
@@ -1,3 +1,6 @@
+import os
+
+
 def fib(b):
     n = int(b)
     if n == 0: 
diff --git a/src/claimed/components/util/cosutils.py b/src/claimed/components/util/cosutils.py
index 8dee5445..a4913a06 100644
--- a/src/claimed/components/util/cosutils.py
+++ b/src/claimed/components/util/cosutils.py
@@ -65,7 +65,7 @@ def _download(s3, cos_file, local_file):
               desc=f'↓ {desc}', leave=True) as pbar:
         with s3.open(cos_file, 'rb') as f_in, open(local_file, 'wb') as f_out:
             while True:
-                chunk = f_in.read(CHUNK_SIZE)
+                chunk = f_in.read(MIN_CHUNK_SIZE)
                 if not chunk:
                     break
                 f_out.write(chunk)
diff --git a/src/claimed/mlx/s3_kv_store.py b/src/claimed/mlx/s3_kv_store.py
index 40b327cd..fdb250fa 100644
--- a/src/claimed/mlx/s3_kv_store.py
+++ b/src/claimed/mlx/s3_kv_store.py
@@ -232,7 +232,7 @@ def main():
     sp.add_argument("--filter", type=json.loads, required=True)
 
     args = parser.parse_args()
-    store = MLX(bucket=args.bucket, store_name=args.store, endpoint_url=args.endpoint)
+    store = S3KVStore(bucket=args.bucket, store_name=args.store, endpoint_url=args.endpoint)
 
     if args.cmd == "put":
         if args.value_file: