diff --git a/swing/src/main/java/info/openrocket/swing/gui/configdialog/MaterialPanel.java b/swing/src/main/java/info/openrocket/swing/gui/configdialog/MaterialPanel.java
index 089e0fdba..c03015a16 100644
--- a/swing/src/main/java/info/openrocket/swing/gui/configdialog/MaterialPanel.java
+++ b/swing/src/main/java/info/openrocket/swing/gui/configdialog/MaterialPanel.java
@@ -28,11 +28,7 @@ import java.awt.Component;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Comparator;
-import java.util.LinkedHashMap;
 import java.util.List;
-import java.util.Map;
 
 /**
  * Panel for configuring a component's material and finish properties.
@@ -63,11 +59,6 @@ public class MaterialPanel extends JPanel implements Invalidatable, Invalidating
                 @Override
                 public void run() {
                     mm.addCustomMaterial();
-                    if (MaterialPanel.this.materialCombo != null) {
-                        MaterialComboBox.updateComboBoxItems(MaterialPanel.this.materialCombo, MaterialGroup.ALL_GROUPS,
-                                mm.getAllMaterials());
-                        MaterialPanel.this.materialCombo.setSelectedItem(mm.getSelectedItem());
-                    }
                 }
             });
         });
@@ -89,8 +80,7 @@ public class MaterialPanel extends JPanel implements Invalidatable, Invalidating
         });
 
         // Material selection combo box
-        this.materialCombo = MaterialComboBox.createComboBox(mm, MaterialGroup.ALL_GROUPS, mm.getAllMaterials(),
-                customMaterialButton, editMaterialsButton);
+        this.materialCombo = MaterialComboBox.createComboBox(mm, customMaterialButton, editMaterialsButton);
         this.materialCombo.setSelectedItem(mm.getSelectedItem());
         this.materialCombo.setToolTipText(trans.get("MaterialPanel.combo.ttip.ComponentMaterialAffects"));
         this.add(this.materialCombo, "spanx 4, growx, wrap paragraph");
@@ -171,10 +161,8 @@ public class MaterialPanel extends JPanel implements Invalidatable, Invalidating
         private static final Translator trans = Application.getTranslator();
 
         public static SearchableAndCategorizableComboBox<MaterialGroup, Material> createComboBox(
-                MaterialModel mm, MaterialGroup[] allGroups, Material[] materials, Component... extraCategoryWidgets) {
-            final Map<MaterialGroup, List<Material>> materialGroupMap =
-                    createMaterialGroupMap(allGroups, materials);
-            return new SearchableAndCategorizableComboBox<>(mm, materialGroupMap,
+                MaterialModel mm, Component... extraCategoryWidgets) {
+            return new SearchableAndCategorizableComboBox<>(mm,
                     trans.get("MaterialPanel.MaterialComboBox.placeholder"), extraCategoryWidgets) {
                 @Override
                 public String getDisplayString(Material item) {
@@ -186,47 +174,5 @@ public class MaterialPanel extends JPanel implements Invalidatable, Invalidating
                 }
             };
         }
-
-        public static void updateComboBoxItems(SearchableAndCategorizableComboBox<MaterialGroup, Material> comboBox,
-                                               MaterialGroup[] allGroups, Material[] materials) {
-            final Map<MaterialGroup, List<Material>> materialGroupMap = createMaterialGroupMap(allGroups, materials);
-            comboBox.updateItems(materialGroupMap);
-            comboBox.invalidate();
-            comboBox.repaint();
-        }
-
-        /**
-         * Create a map of material group and corresponding material.
-         * @param groups the groups
-         * @param materials the materials
-         * @return the map linking the materials to their groups
-         */
-        private static Map<MaterialGroup, List<Material>> createMaterialGroupMap(
-                MaterialGroup[] groups, Material[] materials) {
-            // Sort the groups based on priority (lower number = higher priority)
-            MaterialGroup[] sortedGroups = groups.clone();
-            Arrays.sort(sortedGroups, Comparator.comparingInt(MaterialGroup::getPriority));
-
-            Map<MaterialGroup, List<Material>> map = new LinkedHashMap<>();
-            MaterialGroup materialGroup;
-            for (MaterialGroup group : sortedGroups) {
-                List<Material> itemsForGroup = new ArrayList<>();
-                for (Material material : materials) {
-                    materialGroup = material.getGroup();
-                    if (materialGroup.equals(group)) {
-                        itemsForGroup.add(material);
-                    }
-                }
-                // Sort the types within each group based on priority
-                itemsForGroup.sort(Comparator.comparingInt(Material::getGroupPriority));
-
-                map.put(group, itemsForGroup);
-            }
-
-            // Remove empty groups
-            map.entrySet().removeIf(entry -> entry.getValue().isEmpty());
-
-            return map;
-        }
     }
 }
diff --git a/swing/src/main/java/info/openrocket/swing/gui/simulation/FlightDataComboBox.java b/swing/src/main/java/info/openrocket/swing/gui/simulation/FlightDataComboBox.java
index cd74bb6f0..49ab8eef1 100644
--- a/swing/src/main/java/info/openrocket/swing/gui/simulation/FlightDataComboBox.java
+++ b/swing/src/main/java/info/openrocket/swing/gui/simulation/FlightDataComboBox.java
@@ -17,9 +17,8 @@ import java.util.Map;
 public class FlightDataComboBox extends JComboBox<FlightDataType> {
 	private static final Translator trans = Application.getTranslator();
 
-	public static SearchableAndCategorizableComboBox<FlightDataTypeGroup, FlightDataType> createComboBox(FlightDataTypeGroup[] allGroups, FlightDataType[] types) {
-		final Map<FlightDataTypeGroup, List<FlightDataType>> typeGroupMap = createFlightDataGroupMap(allGroups, types);
-		return new SearchableAndCategorizableComboBox<>(typeGroupMap, trans.get("FlightDataComboBox.placeholder"));
+	public static SearchableAndCategorizableComboBox<FlightDataTypeGroup, FlightDataType> createComboBox(List<FlightDataType> types) {
+		return new SearchableAndCategorizableComboBox<>(types, trans.get("FlightDataComboBox.placeholder"));
 	}
 
 	/**
diff --git a/swing/src/main/java/info/openrocket/swing/gui/simulation/SimulationPlotPanel.java b/swing/src/main/java/info/openrocket/swing/gui/simulation/SimulationPlotPanel.java
index 9b3b60004..5a224c6b0 100644
--- a/swing/src/main/java/info/openrocket/swing/gui/simulation/SimulationPlotPanel.java
+++ b/swing/src/main/java/info/openrocket/swing/gui/simulation/SimulationPlotPanel.java
@@ -173,7 +173,7 @@ public class SimulationPlotPanel extends JPanel {
 		
 		//// X axis type:
 		this.add(new JLabel(trans.get("simplotpanel.lbl.Xaxistype")), "spanx, split");
-		domainTypeSelector = FlightDataComboBox.createComboBox(FlightDataTypeGroup.ALL_GROUPS, types);
+		domainTypeSelector = FlightDataComboBox.createComboBox(Arrays.asList(types));
 		domainTypeSelector.setSelectedItem(configuration.getDomainAxisType());
 		domainTypeSelector.addItemListener(new ItemListener() {
 			@Override
@@ -497,7 +497,7 @@ public class SimulationPlotPanel extends JPanel {
 			
 			this.index = plotIndex;
 			
-			typeSelector = FlightDataComboBox.createComboBox(FlightDataTypeGroup.ALL_GROUPS, types);
+			typeSelector = FlightDataComboBox.createComboBox(Arrays.asList(types));
 			typeSelector.setSelectedItem(type);
 			typeSelector.addItemListener(new ItemListener() {
 				@Override
diff --git a/swing/src/main/java/info/openrocket/swing/gui/widgets/SearchableAndCategorizableComboBox.java b/swing/src/main/java/info/openrocket/swing/gui/widgets/SearchableAndCategorizableComboBox.java
index 656e7f0a6..6894eaa96 100644
--- a/swing/src/main/java/info/openrocket/swing/gui/widgets/SearchableAndCategorizableComboBox.java
+++ b/swing/src/main/java/info/openrocket/swing/gui/widgets/SearchableAndCategorizableComboBox.java
@@ -28,6 +28,8 @@ import java.awt.Component;
 import java.awt.EventQueue;
 import java.awt.Graphics;
 import java.awt.Point;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
 import java.awt.event.FocusAdapter;
 import java.awt.event.FocusEvent;
 import java.awt.event.KeyAdapter;
@@ -45,8 +47,10 @@ import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import java.util.SortedSet;
+import java.util.TreeMap;
 import java.util.TreeSet;
 import java.util.Vector;
 
@@ -63,12 +67,12 @@ public class SearchableAndCategorizableComboBox<G extends Group, T extends Group
 	private static final int CHECKMARK_X_OFFSET = 5;
 	private static final int CHECKMARK_Y_OFFSET = 5;
 
-	private final String placeHolderText;
+	private String placeHolderText;
 	private JPopupMenu categoryPopup;
 	private JPopupMenu searchPopup;
 	private PlaceholderTextField searchFieldCategory;
 	private PlaceholderTextField searchFieldSearch;
-	private final Component[] extraCategoryWidgets;
+	private Component[] extraCategoryWidgets;
 	private JList<T> filteredList;
 
 	private Map<G, List<T>> itemGroupMap;
@@ -84,19 +88,34 @@ public class SearchableAndCategorizableComboBox<G extends Group, T extends Group
 
 	/**
 	 * Create a searchable and categorizable combo box.
-	 * @param itemGroupMap the map of items and their corresponding groups
 	 * @param placeHolderText the placeholder text for the search field (when no text is entered)
 	 * @param extraCategoryWidgets extra widgets to add to the category popup. Each widget will be added as a separate menu item.
 	 */
-	public SearchableAndCategorizableComboBox(ComboBoxModel<T> model, Map<G, List<T>> itemGroupMap, String placeHolderText,
+	public SearchableAndCategorizableComboBox(ComboBoxModel<T> model, String placeHolderText,
 											  Component... extraCategoryWidgets) {
 		super(model != null ? model : new DefaultComboBoxModel<>());
+		List<T> items = new ArrayList<>();
+		for (int i = 0; i < Objects.requireNonNull(model).getSize(); i++) {
+			items.add(model.getElementAt(i));
+		}
+
+		init(model, constructItemGroupMapFromList(items), placeHolderText, extraCategoryWidgets);
+	}
+
+	public SearchableAndCategorizableComboBox(List<T> allItems, String placeHolderText, Component... extraCategoryWidgets) {
+		super();
+
+		init(null, constructItemGroupMapFromList(allItems), placeHolderText, extraCategoryWidgets);
+	}
+
+	private void init(ComboBoxModel<T> model, Map<G, List<T>> itemGroupMap, String placeHolderText, Component... extraCategoryWidgets) {
 		setEditable(false);
 
 		initColors();
 
 		this.extraCategoryWidgets = extraCategoryWidgets;
 		this.placeHolderText = placeHolderText;
+		this.itemGroupMap = itemGroupMap;
 		updateItems(itemGroupMap);
 		setupMainRenderer();
 
@@ -105,10 +124,6 @@ public class SearchableAndCategorizableComboBox<G extends Group, T extends Group
 		addMouseListeners();
 	}
 
-	public SearchableAndCategorizableComboBox(Map<G, List<T>> itemGroupMap, String placeHolderText, Component... extraCategoryWidgets) {
-		this(null, itemGroupMap, placeHolderText, extraCategoryWidgets);
-	}
-
 	private static void initColors() {
 		updateColors();
 		UITheme.Theme.addUIThemeChangeListener(SearchableAndCategorizableComboBox::updateColors);
@@ -118,6 +133,21 @@ public class SearchableAndCategorizableComboBox<G extends Group, T extends Group
 		textSelectionBackground = GUIUtil.getUITheme().getTextSelectionBackgroundColor();
 	}
 
+	private Map<G, List<T>> constructItemGroupMapFromList(List<T> items) {
+		Map<G, List<T>> itemGroupMap = new TreeMap<>(new Comparator<G>() {
+			@Override
+			public int compare(G g1, G g2) {
+				return Integer.compare(g1.getPriority(), g2.getPriority());
+			}
+		});
+
+		for (T item : items) {
+			G group = item.getGroup();
+			itemGroupMap.computeIfAbsent(group, k -> new ArrayList<>()).add(item);
+		}
+		return itemGroupMap;
+	}
+
 	public void setupMainRenderer() {
 		setRenderer(new DefaultListCellRenderer() {
 			@Override
@@ -173,20 +203,6 @@ public class SearchableAndCategorizableComboBox<G extends Group, T extends Group
 		repaint();
 	}
 
-	private void updateItemsFromModel() {
-		ComboBoxModel<T> model = getModel();
-		Map<G, List<T>> newGroupMap = new HashMap<>();
-
-		for (int i = 0; i < model.getSize(); i++) {
-			T item = model.getElementAt(i);
-			G group = item.getGroup();
-			newGroupMap.computeIfAbsent(group, k -> new ArrayList<>()).add(item);
-		}
-
-		Map<G, List<T>> newItemGroupMap = new HashMap<>(newGroupMap);
-		updateItems(newItemGroupMap);
-	}
-
 	private List<T> extractItemsFromMap(Map<G, List<T>> itemGroupMap) {
 		Set<T> uniqueItems = new HashSet<>(); // Use a Set to ensure uniqueness
 		for (G group : itemGroupMap.keySet()) {
@@ -425,6 +441,12 @@ public class SearchableAndCategorizableComboBox<G extends Group, T extends Group
 				updateItemsFromModel();
 			}
 		});
+		addActionListener(new ActionListener() {
+			@Override
+			public void actionPerformed(ActionEvent e) {
+				model.setSelectedItem(SearchableAndCategorizableComboBox.this.getSelectedItem());
+			}
+		});
 	}
 
 	private void setupSearchFieldListeners() {