diff --git a/CHANGELOG.md b/CHANGELOG.md
index 99f46e16..12186a34 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,11 @@
 ### Changed
 - Allow `QuamBase.get_reference(attr)` to return a reference of one of its attributes
 
+### Fixed
+- Fix quam object instantiation error when a parameter type uses pipe operator
+- Allow int keys to be serialised / loaded in QuAM using JSONSerialiser
+
+
 ## [0.3.3]
 ### Added
 - Added the following parameters to `IQChannel`: `RF_frequency`, `LO_frequency`, `intermediate_frequency`
diff --git a/docs/installation.md b/docs/installation.md
index fab721f9..31bdf4e7 100644
--- a/docs/installation.md
+++ b/docs/installation.md
@@ -4,7 +4,7 @@
 
 /// tab | For Windows
 - Windows 10 (build 1809 and later), or Windows 11
-- Python 3.9 or higher, we recommend Python 3.10 or higher
+- 3.8 ≤ Python ≤ 3.11, we recommend Python 3.10 or 3.11
     <!-- For Python 3.8 and 3.9, please see additional notes (TODO add note reference) -->
 - [Git version control system](https://git-scm.com/), or a Git GUI such as [GitHub Desktop](https://desktop.github.com/) or [GitKraken](https://www.gitkraken.com/)
 
diff --git a/quam/core/quam_instantiation.py b/quam/core/quam_instantiation.py
index 57680cf4..e1bd0720 100644
--- a/quam/core/quam_instantiation.py
+++ b/quam/core/quam_instantiation.py
@@ -1,4 +1,6 @@
 from __future__ import annotations
+import sys
+import types
 import typing
 from typing import TYPE_CHECKING, Dict, Any
 from inspect import isclass
@@ -16,6 +18,12 @@
     from quam.core import QuamBase
 
 
+if sys.version_info < (3, 10):
+    union_types = (typing.Union,)
+else:
+    union_types = [typing.Union, types.UnionType]
+
+
 def instantiate_attrs_from_dict(
     attr_dict: dict,
     required_type: type,
@@ -224,7 +232,7 @@ def instantiate_attr(
         )
         if typing.get_origin(expected_type) == dict:
             expected_type = dict
-    elif typing.get_origin(expected_type) == typing.Union:
+    elif typing.get_origin(expected_type) in union_types:
         for union_type in typing.get_args(expected_type):
             try:
                 instantiated_attr = instantiate_attr(
diff --git a/quam/serialisation/json.py b/quam/serialisation/json.py
index 3d7b9306..e2d56655 100644
--- a/quam/serialisation/json.py
+++ b/quam/serialisation/json.py
@@ -166,7 +166,7 @@ def load(
 
             metadata["default_filename"] = path.name
             with open(path, "r") as f:
-                contents = json.load(f)
+                contents = json.load(f, object_hook=convert_int_keys)
         elif path.is_dir():
             metadata["default_foldername"] = str(path)
             for file in path.iterdir():
@@ -183,3 +183,17 @@ def load(
                     metadata["content_mapping"][file.name] = list(file_contents.keys())
 
         return contents, metadata
+
+
+def convert_int_keys(obj):
+    """Convert dictionary keys to integers if possible."""
+    if not isinstance(obj, dict):
+        return obj
+
+    new_obj = {}
+    for key, value in obj.items():
+        if key.isdigit():
+            key = int(key)
+        new_obj[key] = value
+
+    return new_obj
diff --git a/quam/utils/config.py b/quam/utils/config.py
index e46fdaef..8f5619cc 100644
--- a/quam/utils/config.py
+++ b/quam/utils/config.py
@@ -10,7 +10,16 @@ def generate_config_final_actions(qua_config):
     Args:
         qua_config (dict): The generated qua config.
     """
+    # Add default dc offset 0V to all analog outputs and inputs if not set
     for controller_cfg in qua_config["controllers"].values():
+        for fem in controller_cfg.get("fems", {}).values():
+            if fem.get("type") != "LF":
+                continue
+            for analog_output in fem.get("analog_outputs", {}).values():
+                analog_output.setdefault("offset", 0.0)
+            for analog_input in fem.get("analog_inputs", {}).values():
+                analog_input.setdefault("offset", 0.0)
+
         if "analog_outputs" in controller_cfg:
             for analog_output in controller_cfg["analog_outputs"].values():
                 analog_output.setdefault("offset", 0.0)
diff --git a/tests/config/test_config_final_actions.py b/tests/config/test_config_final_actions.py
new file mode 100644
index 00000000..e7d0f538
--- /dev/null
+++ b/tests/config/test_config_final_actions.py
@@ -0,0 +1,139 @@
+from quam.utils.config import generate_config_final_actions
+
+
+def test_config_no_overwrite_existing_offset():
+    cfg = {
+        "controllers": {
+            "con1": {
+                "analog_outputs": {1: {"offset": 0.5}},
+                "analog_inputs": {2: {"offset": 0.5}},
+            },
+        },
+    }
+
+    generate_config_final_actions(cfg)
+
+    assert cfg == {
+        "controllers": {
+            "con1": {
+                "analog_outputs": {1: {"offset": 0.5}},
+                "analog_inputs": {2: {"offset": 0.5}},
+            },
+        },
+    }
+
+
+def test_config_default_offset():
+    cfg = {
+        "controllers": {
+            "con1": {
+                "analog_outputs": {1: {}},
+                "analog_inputs": {2: {}},
+            },
+        },
+    }
+
+    generate_config_final_actions(cfg)
+
+    assert cfg == {
+        "controllers": {
+            "con1": {
+                "analog_outputs": {1: {"offset": 0.0}},
+                "analog_inputs": {2: {"offset": 0.0}},
+            },
+        },
+    }
+
+
+def test_config_default_offset_LF_FEM():
+    cfg = {
+        "controllers": {
+            "con1": {
+                "fems": {
+                    2: {
+                        "type": "LF",
+                        "analog_outputs": {1: {}},
+                        "analog_inputs": {2: {}},
+                    },
+                },
+            },
+        },
+    }
+
+    generate_config_final_actions(cfg)
+
+    assert cfg == {
+        "controllers": {
+            "con1": {
+                "fems": {
+                    2: {
+                        "type": "LF",
+                        "analog_outputs": {1: {"offset": 0.0}},
+                        "analog_inputs": {2: {"offset": 0.0}},
+                    },
+                },
+            },
+        },
+    }
+
+
+def test_config_no_overwrite_existing_offset_LF_FEM():
+    cfg = {
+        "controllers": {
+            "con1": {
+                "fems": {
+                    2: {
+                        "type": "LF",
+                        "analog_outputs": {1: {"offset": 0.5}},
+                        "analog_inputs": {2: {"offset": 0.5}},
+                    },
+                },
+            },
+        },
+    }
+
+    generate_config_final_actions(cfg)
+
+    assert cfg == {
+        "controllers": {
+            "con1": {
+                "fems": {
+                    2: {
+                        "type": "LF",
+                        "analog_outputs": {1: {"offset": 0.5}},
+                        "analog_inputs": {2: {"offset": 0.5}},
+                    },
+                },
+            },
+        },
+    }
+
+
+def test_config_default_offset_no_outputs_inputs_entries():
+    cfg = {"controllers": {"con1": {}}}
+
+    generate_config_final_actions(cfg)
+
+    assert cfg == {"controllers": {"con1": {}}}
+
+
+def test_config_default_offset_no_outputs_inputs():
+    cfg = {
+        "controllers": {
+            "con1": {
+                "analog_outputs": {},
+                "analog_inputs": {},
+            }
+        }
+    }
+
+    generate_config_final_actions(cfg)
+
+    assert cfg == {
+        "controllers": {
+            "con1": {
+                "analog_outputs": {},
+                "analog_inputs": {},
+            }
+        }
+    }
diff --git a/tests/instantiation/test_instantiation.py b/tests/instantiation/test_instantiation.py
index 7aa293ff..f6c0da63 100644
--- a/tests/instantiation/test_instantiation.py
+++ b/tests/instantiation/test_instantiation.py
@@ -1,6 +1,8 @@
 import pytest
 from typing import List, Literal, Optional, Tuple, Union
 
+from pytest_cov.engine import sys
+
 from quam.core import QuamRoot, QuamComponent, quam_dataclass
 from quam.core.quam_classes import QuamDict
 from quam.examples.superconducting_qubits.components import Transmon
@@ -339,6 +341,7 @@ def test_instantiate_dict_referenced():
 
     assert attrs == {"test_attr": "#./reference"}
 
+
 @quam_dataclass
 class TestQuamComponent(QuamComponent):
     a: int
@@ -357,3 +360,19 @@ class TestQuamUnion(QuamComponent):
 
     with pytest.raises(TypeError):
         instantiate_quam_class(TestQuamUnion, {"union_val": {"a": "42"}})
+
+
+@pytest.mark.skipif(sys.version_info < (3, 10), reason="requires python3.10 or higher")
+def test_instantiation_pipe_union_type():
+    @quam_dataclass
+    class TestQuamUnion(QuamComponent):
+        union_val: int | TestQuamComponent
+
+    obj = instantiate_quam_class(TestQuamUnion, {"union_val": 42})
+    assert obj.union_val == 42
+
+    obj = instantiate_quam_class(TestQuamUnion, {"union_val": {"a": 42}})
+    assert obj.union_val.a == 42
+
+    with pytest.raises(TypeError):
+        instantiate_quam_class(TestQuamUnion, {"union_val": {"a": "42"}})
diff --git a/tests/serialisation/test_json_serialisation.py b/tests/serialisation/test_json_serialisation.py
index b7695e5f..167f4c4d 100644
--- a/tests/serialisation/test_json_serialisation.py
+++ b/tests/serialisation/test_json_serialisation.py
@@ -1,4 +1,5 @@
 import json
+from typing import Dict
 import pytest
 
 from quam.serialisation import JSONSerialiser
@@ -107,3 +108,28 @@ def test_component_mamping_ignore(tmp_path):
             "a": 4,
         }
     }
+
+
+@quam_dataclass
+class QuAMWithIntDict(QuamRoot):
+    a: int
+    d: Dict[int, str]
+
+
+def test_serialise_int_dict_keys(tmp_path):
+    quam_root = QuAMWithIntDict(a=1, d={1: "a", 2: "b"})
+
+    serialiser = JSONSerialiser()
+    path = tmp_path / "quam_root.json"
+    serialiser.save(quam_root, path)
+
+    d, _ = serialiser.load(path)
+
+    assert d == {
+        "a": 1,
+        "d": {
+            1: "a",
+            2: "b",
+        },
+        "__class__": "test_json_serialisation.QuAMWithIntDict",
+    }