diff --git a/src/bonsai/bonsai/bim/module/geometry/operator.py b/src/bonsai/bonsai/bim/module/geometry/operator.py
index f41a7c7edc..4bdef85702 100644
--- a/src/bonsai/bonsai/bim/module/geometry/operator.py
+++ b/src/bonsai/bonsai/bim/module/geometry/operator.py
@@ -1070,11 +1070,20 @@ class OverrideDuplicateMove(bpy.types.Operator):
         tool.Root.reload_item_decorator()
 
     @staticmethod
-    def process_arrays(self, context):
+    def process_arrays(
+        self, context: bpy.types.Context
+    ) -> tuple[dict[bpy.types.Object, Any], set[ifcopenshell.entity_instance]]:
+        """ "Process arrays for currently selected objects.
+
+        :return: A tuple of two elements:\n
+            - dictionary of objects and their array data. Those objects are safe to duplicate and regenerate arrays using the data.\n
+            - set of array children objects. Those objects can be ignored during duplication, they will be recreated automatically
+            when arrays are regenerated for objects from the dictionary.
+        """
         selected_objects = set(context.selected_objects)
         array_parents = set()
-        arrays_to_create = dict()
-        array_children = set()  # will be ignored during the duplication
+        arrays_to_create: dict[bpy.types.Object, Any] = dict()
+        array_children: set[ifcopenshell.entity_instance] = set()  # will be ignored during the duplication
 
         for obj in context.selected_objects:
             element = tool.Ifc.get_entity(obj)
diff --git a/src/bonsai/bonsai/core/pset.py b/src/bonsai/bonsai/core/pset.py
index 5a059f4833..477f023cc2 100644
--- a/src/bonsai/bonsai/core/pset.py
+++ b/src/bonsai/bonsai/core/pset.py
@@ -65,7 +65,7 @@ def add_pset(
 
 def enable_pset_editing(
     pset_tool: tool.Pset,
-    pset: ifcopenshell.entity_instance,
+    pset: Union[ifcopenshell.entity_instance, None],
     pset_name: str,
     pset_type: tool.Pset.PSET_TYPE,
     obj_name: str,
diff --git a/src/bonsai/bonsai/tool/model.py b/src/bonsai/bonsai/tool/model.py
index 19e0660c69..2291d6862e 100644
--- a/src/bonsai/bonsai/tool/model.py
+++ b/src/bonsai/bonsai/tool/model.py
@@ -675,13 +675,14 @@ class Model(bonsai.core.tool.Model):
 
             # remove constraints
             obj = tool.Ifc.get_object(element)
+            assert isinstance(obj, bpy.types.Object)
             if not array_pset_data:  # skip array parents
                 constraint = next((c for c in obj.constraints if c.type == "CHILD_OF"), None)
                 if constraint:
                     matrix = obj.matrix_world.copy()
                     obj.constraints.remove(constraint)
-                    # keep the matrix before the constraint
-                    # otherwise object will jump to some previous position
+                    # Keep the matrix before removing the constraint,
+                    # otherwise object will jump to some previous position.
                     obj.matrix_world = matrix
                 tool.Blender.lock_transform(obj, False)
 
diff --git a/src/ifcopenshell-python/ifcopenshell/api/pset/edit_pset.py b/src/ifcopenshell-python/ifcopenshell/api/pset/edit_pset.py
index eddc927d1a..d93bb9ebb9 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/pset/edit_pset.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/pset/edit_pset.py
@@ -410,7 +410,12 @@ class Usecase:
 
         raise TypeError(f"'{self.settings['pset']}' is not a valid pset")
 
-    def get_primary_measure_type(self, name, old_value=None, new_value=None):
+    def get_primary_measure_type(
+        self,
+        name: str,
+        old_value: Optional[ifcopenshell.entity_instance] = None,
+        new_value: Optional[Union[ifcopenshell.entity_instance, str, float, bool, int]] = None,
+    ) -> Union[str, None]:
         if old_value:
             return old_value.is_a()
         if self.pset_template:
@@ -418,7 +423,7 @@ class Usecase:
                 if prop_template.Name != name:
                     continue
                 return prop_template.PrimaryMeasureType or "IfcLabel"
-        if new_value and hasattr(new_value, "is_a"):
+        if isinstance(new_value, ifcopenshell.entity_instance):
             return new_value.is_a()
         elif new_value is not None:
             if isinstance(new_value, str):