diff --git a/CHANGELOG.md b/CHANGELOG.md
index cdfccd059..3ea18cfbf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -34,6 +34,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Operations
 
 - Allow `cloudpickle` >= 3.0.0
+- Allow `cloudpickle` >= 3.0.0 in SDK-only installs
 - Remove `boto3` dependency from `tests/requirements.txt`
 
 ## [0.232.0-rc.0] - 2023-12-01
diff --git a/covalent/_api/apiclient.py b/covalent/_api/apiclient.py
index c4c2a5492..d3be6bd4a 100644
--- a/covalent/_api/apiclient.py
+++ b/covalent/_api/apiclient.py
@@ -33,7 +33,7 @@ def __init__(self, dispatcher_addr: str, adapter: HTTPAdapter = None, auto_raise
         self.adapter = adapter
         self.auto_raise = auto_raise
 
-    def prepare_headers(self, **kwargs):
+    def prepare_headers(self, kwargs):
         extra_headers = CovalentAPIClient.get_extra_headers()
         headers = kwargs.get("headers", {})
         if headers:
@@ -42,7 +42,7 @@ def prepare_headers(self, **kwargs):
         return headers
 
     def get(self, endpoint: str, **kwargs):
-        headers = self.prepare_headers(**kwargs)
+        headers = self.prepare_headers(kwargs)
         url = self.dispatcher_addr + endpoint
         try:
             with requests.Session() as session:
@@ -62,7 +62,7 @@ def get(self, endpoint: str, **kwargs):
         return r
 
     def put(self, endpoint: str, **kwargs):
-        headers = self.prepare_headers()
+        headers = self.prepare_headers(kwargs)
         url = self.dispatcher_addr + endpoint
         try:
             with requests.Session() as session:
@@ -81,7 +81,7 @@ def put(self, endpoint: str, **kwargs):
         return r
 
     def post(self, endpoint: str, **kwargs):
-        headers = self.prepare_headers()
+        headers = self.prepare_headers(kwargs)
         url = self.dispatcher_addr + endpoint
         try:
             with requests.Session() as session:
@@ -100,7 +100,7 @@ def post(self, endpoint: str, **kwargs):
         return r
 
     def delete(self, endpoint: str, **kwargs):
-        headers = self.prepare_headers()
+        headers = self.prepare_headers(kwargs)
         url = self.dispatcher_addr + endpoint
         try:
             with requests.Session() as session:
diff --git a/covalent/_dispatcher_plugins/local.py b/covalent/_dispatcher_plugins/local.py
index 8760cec96..f5ad26bdd 100644
--- a/covalent/_dispatcher_plugins/local.py
+++ b/covalent/_dispatcher_plugins/local.py
@@ -14,6 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import os
 import tempfile
 from copy import deepcopy
 from functools import wraps
@@ -616,14 +617,16 @@ def _upload_asset(local_uri, remote_uri):
         local_path = local_uri
 
     with open(local_path, "rb") as reader:
-        app_log.debug(f"uploading to {remote_uri}")
+        content_length = os.path.getsize(local_path)
         f = furl(remote_uri)
         scheme = f.scheme
         host = f.host
         port = f.port
         dispatcher_addr = f"{scheme}://{host}:{port}"
-        endpoint = str(f.path)
+        endpoint = f"{str(f.path)}?{str(f.query)}"
         api_client = APIClient(dispatcher_addr)
-
-        r = api_client.put(endpoint, data=reader)
+        if content_length == 0:
+            r = api_client.put(endpoint, headers={"Content-Length": "0"}, data=reader.read())
+        else:
+            r = api_client.put(endpoint, data=reader)
         r.raise_for_status()
diff --git a/covalent/_workflow/electron.py b/covalent/_workflow/electron.py
index 12f18cbf5..b38ea3d5e 100644
--- a/covalent/_workflow/electron.py
+++ b/covalent/_workflow/electron.py
@@ -915,6 +915,7 @@ def _build_sublattice_graph(sub: Lattice, json_parent_metadata: str, *args, **kw
         return recv_manifest.model_dump_json()
 
     except Exception as ex:
+        if os.environ.get("COVALENT_DISABLE_LEGACY_SUBLATTICES") == "1":
+            raise
         # Fall back to legacy sublattice handling
-        print("Falling back to legacy sublattice handling")
         return sub.serialize_to_json()
diff --git a/requirements-client.txt b/requirements-client.txt
index ede6a20e3..3c93879ed 100644
--- a/requirements-client.txt
+++ b/requirements-client.txt
@@ -1,6 +1,6 @@
 aiofiles>=0.8.0
 aiohttp>=3.8.1
-cloudpickle>=2.0.0,<3
+cloudpickle>=2.0.0
 dask[distributed]>=2022.6.0
 filelock>=3.12.2
 furl>=2.1.3
diff --git a/tests/covalent_tests/api/apiclient_test.py b/tests/covalent_tests/api/apiclient_test.py
new file mode 100644
index 000000000..20d22cb5a
--- /dev/null
+++ b/tests/covalent_tests/api/apiclient_test.py
@@ -0,0 +1,44 @@
+# Copyright 2023 Agnostiq Inc.
+#
+# This file is part of Covalent.
+#
+# Licensed under the Apache License 2.0 (the "License"). A copy of the
+# License may be obtained with this software package or at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Use of this file is prohibited except in compliance with the License.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+"""Unit tests for the API client"""
+
+import json
+from unittest.mock import MagicMock
+
+import pytest
+
+from covalent._api.apiclient import CovalentAPIClient
+
+
+@pytest.fixture
+def mock_session():
+    sess = MagicMock()
+
+
+def test_header_injection(mocker):
+    extra_headers = {"x-custom-header": "value"}
+    headers = {"Content-Length": "128"}
+    expected_headers = headers.copy()
+    expected_headers.update(extra_headers)
+    mock_session = MagicMock()
+    environ = {"COVALENT_EXTRA_HEADERS": json.dumps(extra_headers)}
+    mocker.patch("os.environ", environ)
+    mocker.patch("requests.Session.__enter__", return_value=mock_session)
+
+    CovalentAPIClient("http://localhost").post("/docs", headers=headers)
+    mock_session.post.assert_called_with("http://localhost/docs", headers=expected_headers)
diff --git a/tests/covalent_tests/workflow/electron_test.py b/tests/covalent_tests/workflow/electron_test.py
index a3db76bb7..8925d9bae 100644
--- a/tests/covalent_tests/workflow/electron_test.py
+++ b/tests/covalent_tests/workflow/electron_test.py
@@ -201,6 +201,52 @@ def workflow(x):
             assert parent_metadata[k] == lattice.metadata[k]
 
 
+def test_build_sublattice_graph_prevent_fallback(mocker):
+    """
+    Test preventing falling back to monolithic sublattice dispatch.
+    """
+    dispatch_id = "test_build_sublattice_graph_prevent_fallback"
+
+    @ct.electron
+    def task(x):
+        return x
+
+    @ct.lattice
+    def workflow(x):
+        return task(x)
+
+    parent_metadata = {
+        "executor": "parent_executor",
+        "executor_data": {},
+        "workflow_executor": "my_postprocessor",
+        "workflow_executor_data": {},
+        "hooks": {
+            "deps": {"bash": None, "pip": None},
+            "call_before": [],
+            "call_after": [],
+        },
+        "triggers": "mock-trigger",
+        "qelectron_data_exists": False,
+        "results_dir": None,
+    }
+
+    # Omit the required environment variables
+    mock_environ = {"COVALENT_DISABLE_LEGACY_SUBLATTICES": "1"}
+
+    mock_reg = mocker.patch(
+        "covalent._dispatcher_plugins.local.LocalDispatcher.register_manifest",
+    )
+
+    mock_upload_assets = mocker.patch(
+        "covalent._dispatcher_plugins.local.LocalDispatcher.upload_assets",
+    )
+
+    mocker.patch("os.environ", mock_environ)
+
+    with pytest.raises(Exception):
+        json_lattice = _build_sublattice_graph(workflow, json.dumps(parent_metadata), 1)
+
+
 def test_wait_for_building():
     """Test to check whether the graph is built correctly with `wait_for`."""
 
diff --git a/tests/functional_tests/file_transfer_test.py b/tests/functional_tests/file_transfer_test.py
index ea5f4029d..36d9ff2ac 100644
--- a/tests/functional_tests/file_transfer_test.py
+++ b/tests/functional_tests/file_transfer_test.py
@@ -180,7 +180,7 @@ def workflow():
     rm._delete_result(dispatch_id)
 
     assert len(workflow_result.result) == 2
-    assert workflow_result.result == (MOCK_CONTENTS, MOCK_CONTENTS)
+    assert workflow_result.result == [MOCK_CONTENTS, MOCK_CONTENTS]
     for f in [source_file_1, dest_file_1, source_file_2, dest_file_2]:
         f.unlink()