diff --git a/InvenTree/InvenTree/api_version.py b/InvenTree/InvenTree/api_version.py
index 0901fdc13b..2618e9d0b5 100644
--- a/InvenTree/InvenTree/api_version.py
+++ b/InvenTree/InvenTree/api_version.py
@@ -2,11 +2,15 @@
 
 
 # InvenTree API version
-INVENTREE_API_VERSION = 137
+INVENTREE_API_VERSION = 138
 
 """
 Increment this API version number whenever there is a significant change to the API that any clients need to know about
 
+v138 -> 2023-10-11 : https://github.com/inventree/InvenTree/pull/5679
+    - Settings keys are no longer case sensitive
+    - Include settings units in API serializer
+
 v137 -> 2023-10-04 : https://github.com/inventree/InvenTree/pull/5588
     - Adds StockLocationType API endpoints
     - Adds custom_icon, location_type to StockLocation endpoint
@@ -89,7 +93,7 @@ v113 -> 2023-05-13 : https://github.com/inventree/InvenTree/pull/4800
     - Adds API endpoints for scrapping a build output
 
 v112 -> 2023-05-13: https://github.com/inventree/InvenTree/pull/4741
-    - Adds flag use_pack_size to the stock addition API, which allows addings packs
+    - Adds flag use_pack_size to the stock addition API, which allows adding packs
 
 v111 -> 2023-05-02 : https://github.com/inventree/InvenTree/pull/4367
     - Adds tags to the Part serializer
@@ -169,7 +173,7 @@ v90 -> 2023-01-25 : https://github.com/inventree/InvenTree/pull/4186/files
 
 v89 -> 2023-01-25 : https://github.com/inventree/InvenTree/pull/4214
     - Adds updated field to SupplierPart API
-    - Adds API date orddering for supplier part list
+    - Adds API date ordering for supplier part list
 
 v88 -> 2023-01-17: https://github.com/inventree/InvenTree/pull/4225
     - Adds 'priority' field to Build model and api endpoints
diff --git a/InvenTree/InvenTree/serializers.py b/InvenTree/InvenTree/serializers.py
index 8260fb05ef..a209f5c329 100644
--- a/InvenTree/InvenTree/serializers.py
+++ b/InvenTree/InvenTree/serializers.py
@@ -298,7 +298,11 @@ class UserSerializer(InvenTreeModelSerializer):
             'username',
             'first_name',
             'last_name',
-            'email'
+            'email',
+        ]
+
+        read_only_fields = [
+            'username',
         ]
 
 
diff --git a/InvenTree/common/api.py b/InvenTree/common/api.py
index d77bddc3ca..c13ae456dd 100644
--- a/InvenTree/common/api.py
+++ b/InvenTree/common/api.py
@@ -229,9 +229,9 @@ class GlobalSettingsDetail(RetrieveUpdateAPI):
 
     def get_object(self):
         """Attempt to find a global setting object with the provided key."""
-        key = self.kwargs['key']
+        key = str(self.kwargs['key']).upper()
 
-        if key not in common.models.InvenTreeSetting.SETTINGS.keys():
+        if key.startswith('_') or key not in common.models.InvenTreeSetting.SETTINGS.keys():
             raise NotFound()
 
         return common.models.InvenTreeSetting.get_setting_object(
@@ -296,9 +296,9 @@ class UserSettingsDetail(RetrieveUpdateAPI):
 
     def get_object(self):
         """Attempt to find a user setting object with the provided key."""
-        key = self.kwargs['key']
+        key = str(self.kwargs['key']).upper()
 
-        if key not in common.models.InvenTreeUserSetting.SETTINGS.keys():
+        if key.startswith('_') or key not in common.models.InvenTreeUserSetting.SETTINGS.keys():
             raise NotFound()
 
         return common.models.InvenTreeUserSetting.get_setting_object(
diff --git a/InvenTree/common/models.py b/InvenTree/common/models.py
index a07697130c..a198e29e82 100644
--- a/InvenTree/common/models.py
+++ b/InvenTree/common/models.py
@@ -205,6 +205,12 @@ class BaseInvenTreeSetting(models.Model):
         If a particular setting is not present, create it with the default value
         """
 
+        cache_key = f"BUILD_DEFAULT_VALUES:{str(cls.__name__)}"
+
+        if InvenTree.helpers.str2bool(cache.get(cache_key, False)):
+            # Already built default values
+            return
+
         try:
             existing_keys = cls.objects.filter(**kwargs).values_list('key', flat=True)
             settings_keys = cls.SETTINGS.keys()
@@ -224,6 +230,8 @@ class BaseInvenTreeSetting(models.Model):
             logger.exception("Failed to build default values for %s (%s)", str(cls), str(type(exc)))
             pass
 
+        cache.set(cache_key, True, timeout=3600)
+
     def _call_settings_function(self, reference: str, args, kwargs):
         """Call a function associated with a particular setting.
 
@@ -1241,7 +1249,7 @@ class InvenTreeSetting(BaseInvenTreeSetting):
 
         'BARCODE_ENABLE': {
             'name': _('Barcode Support'),
-            'description': _('Enable barcode scanner support'),
+            'description': _('Enable barcode scanner support in the web interface'),
             'default': True,
             'validator': bool,
         },
diff --git a/InvenTree/common/serializers.py b/InvenTree/common/serializers.py
index 4c1d0b5a54..94109eb831 100644
--- a/InvenTree/common/serializers.py
+++ b/InvenTree/common/serializers.py
@@ -51,6 +51,8 @@ class SettingsSerializer(InvenTreeModelSerializer):
 
     value = SettingsValueField()
 
+    units = serializers.CharField(read_only=True)
+
     def get_choices(self, obj):
         """Returns the choices available for a given item."""
         results = []
@@ -81,6 +83,7 @@ class GlobalSettingsSerializer(SettingsSerializer):
             'name',
             'description',
             'type',
+            'units',
             'choices',
             'model_name',
             'api_url',
@@ -103,6 +106,7 @@ class UserSettingsSerializer(SettingsSerializer):
             'description',
             'user',
             'type',
+            'units',
             'choices',
             'model_name',
             'api_url',