diff --git a/PKHeX.Avalonia/App.axaml.cs b/PKHeX.Avalonia/App.axaml.cs
index c284776f7..cdac788b4 100644
--- a/PKHeX.Avalonia/App.axaml.cs
+++ b/PKHeX.Avalonia/App.axaml.cs
@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Linq;
 using Avalonia;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
@@ -34,10 +35,30 @@ public override void OnFrameworkInitializationCompleted()
         if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
         {
             var mainViewModel = new MainWindowViewModel();
-            desktop.MainWindow = new MainWindow
+            var mainWindow = new MainWindow
             {
                 DataContext = mainViewModel,
             };
+            desktop.MainWindow = mainWindow;
+
+            // Auto-load save file on startup, after the window is shown
+            mainWindow.Opened += (_, _) =>
+            {
+                try
+                {
+                    var args = Environment.GetCommandLineArgs().Skip(1).ToArray();
+                    var startup = StartupUtil.GetStartup(args, Settings);
+                    if (startup.SAV is { } sav)
+                    {
+                        var path = sav.Metadata.FilePath ?? string.Empty;
+                        mainViewModel.LoadInitialSave(sav, startup.Entity, path);
+                    }
+                }
+                catch (Exception ex)
+                {
+                    System.Diagnostics.Debug.WriteLine($"Auto-load on startup failed: {ex.Message}");
+                }
+            };
 
             desktop.ShutdownRequested += (_, _) =>
             {
@@ -61,6 +82,11 @@ private void LoadSettings()
         Settings.LocalResources.SetLocalPath(WorkingDirectory);
         SpriteBuilder.LoadSettings(Settings.Sprite);
 
+        // Handle HaX and version tracking (mirrors WinForms FormLoadInitialActions)
+        var args = Environment.GetCommandLineArgs().Skip(1).ToArray();
+        var init = StartupUtil.FormLoadInitialActions(args, Settings, CurrentVersion);
+        HaX = init.HaX;
+
         var language = Settings.Startup.Language;
         LocalizeUtil.InitializeStrings(language);
     }
diff --git a/PKHeX.Avalonia/Controls/SlotChangeManager.cs b/PKHeX.Avalonia/Controls/SlotChangeManager.cs
index 5a0224e15..56b2c7fe2 100644
--- a/PKHeX.Avalonia/Controls/SlotChangeManager.cs
+++ b/PKHeX.Avalonia/Controls/SlotChangeManager.cs
@@ -1,10 +1,12 @@
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using Avalonia.Input;
 using Avalonia.Platform.Storage;
 using PKHeX.Avalonia.ViewModels;
+using PKHeX.Avalonia.ViewModels.Subforms;
 using PKHeX.Core;
 
 namespace PKHeX.Avalonia.Controls;
@@ -23,17 +25,33 @@ public sealed class SlotChangeManager
 
     private readonly SAVEditorViewModel _editor;
 
+    /// <summary>Registered BoxViewer VMs whose slots participate in drag-and-drop.</summary>
+    private readonly List<BoxViewerViewModel> _boxViewers = [];
+
     /// <summary>Tracks the source slot when a drag operation is in progress.</summary>
     private SlotModel? _sourceSlot;
 
     /// <summary>Indicates whether a drag operation is currently in progress.</summary>
     public bool IsDragInProgress { get; private set; }
 
+    /// <summary>Gets the <see cref="SAVEditorViewModel"/> that owns this manager.</summary>
+    public SAVEditorViewModel Editor => _editor;
+
     public SlotChangeManager(SAVEditorViewModel editor)
     {
         _editor = editor;
     }
 
+    /// <summary>
+    /// Registers a <see cref="BoxViewerViewModel"/> so its slots can participate in drag-and-drop.
+    /// </summary>
+    public void RegisterBoxViewer(BoxViewerViewModel viewer) => _boxViewers.Add(viewer);
+
+    /// <summary>
+    /// Unregisters a <see cref="BoxViewerViewModel"/> when its window is closed.
+    /// </summary>
+    public void UnregisterBoxViewer(BoxViewerViewModel viewer) => _boxViewers.Remove(viewer);
+
     /// <summary>
     /// Initiates a drag operation from the given slot.
     /// Call this from <see cref="Avalonia.Input.Pointer"/> move after a press.
@@ -46,7 +64,7 @@ public SlotChangeManager(SAVEditorViewModel editor)
         if (IsDragInProgress)
             return null;
 
-        var pk = _editor.GetSlotPKM(slot);
+        var pk = GetSlotPKM(slot);
         if (pk is null || pk.Species == 0)
             return null;
 
@@ -156,6 +174,12 @@ private void HandleFileDrop(SlotModel destSlot, DragEventArgs e)
                 _editor.PushUndo(undoEntry);
             WriteSlot(destSlot, pk);
             _editor.ReloadSlots();
+            // Refresh box viewer if the drop target was in one
+            foreach (var bv in _boxViewers)
+            {
+                if (bv.BoxSlots.Contains(destSlot))
+                    bv.RefreshBox();
+            }
             _editor.SetStatusMessage?.Invoke($"Loaded {Path.GetFileName(filePath)} into slot.");
         }
         catch (Exception ex)
@@ -179,6 +203,57 @@ private static DropModifier GetDropModifier(KeyModifiers keys)
         return DropModifier.None;
     }
 
+    /// <summary>
+    /// Resolved location of a <see cref="SlotModel"/> within the save file.
+    /// </summary>
+    private readonly record struct ResolvedSlot(int Box, int Index, bool IsParty, BoxViewerViewModel? BoxViewer);
+
+    /// <summary>
+    /// Resolves a <see cref="SlotModel"/> to its (box, index) coordinate by checking
+    /// the main editor's box/party slots and all registered box viewers.
+    /// </summary>
+    private ResolvedSlot? ResolveSlot(SlotModel slot)
+    {
+        // Check main editor box slots
+        int boxIndex = _editor.BoxSlots.IndexOf(slot);
+        if (boxIndex >= 0)
+            return new ResolvedSlot(_editor.CurrentBox, boxIndex, false, null);
+
+        // Check main editor party slots
+        int partyIndex = _editor.PartySlots.IndexOf(slot);
+        if (partyIndex >= 0)
+            return new ResolvedSlot(0, partyIndex, true, null);
+
+        // Check registered box viewers
+        foreach (var bv in _boxViewers)
+        {
+            int bvIndex = bv.BoxSlots.IndexOf(slot);
+            if (bvIndex >= 0)
+                return new ResolvedSlot(bv.CurrentBox, bvIndex, false, bv);
+        }
+
+        return null;
+    }
+
+    /// <summary>
+    /// Gets the PKM at the resolved slot location.
+    /// </summary>
+    private PKM? GetSlotPKM(SlotModel slot)
+    {
+        var sav = _editor.SAV;
+        if (sav is null)
+            return null;
+
+        var resolved = ResolveSlot(slot);
+        if (resolved is null)
+            return null;
+
+        var r = resolved.Value;
+        if (r.IsParty)
+            return sav.GetPartySlotAtIndex(r.Index);
+        return sav.GetBoxSlotAtIndex(r.Box, r.Index);
+    }
+
     /// <summary>
     /// Executes the slot move/swap/clone operation.
     /// </summary>
@@ -188,15 +263,15 @@ private void PerformSlotOperation(SlotModel source, SlotModel dest, DropModifier
         if (sav is null)
             return;
 
-        var sourcePkm = _editor.GetSlotPKM(source);
+        var sourcePkm = GetSlotPKM(source);
         if (sourcePkm is null || sourcePkm.Species == 0)
             return;
 
-        var destPkm = _editor.GetSlotPKM(dest);
+        var destPkm = GetSlotPKM(dest);
         bool destIsEmpty = destPkm is null || destPkm.Species == 0;
 
         // Collect undo entries and push as a single atomic group
-        var entries = new System.Collections.Generic.List<SAVEditorViewModel.SlotChangeEntry>();
+        var entries = new List<SAVEditorViewModel.SlotChangeEntry>();
         var destEntry = CreateUndoEntry(dest);
         if (destEntry is not null)
             entries.Add(destEntry);
@@ -222,8 +297,9 @@ private void PerformSlotOperation(SlotModel source, SlotModel dest, DropModifier
             case DropModifier.Overwrite:
                 // Don't clear source if it's the last party member
                 {
-                    int sourcePartyIdx = _editor.PartySlots.IndexOf(source);
-                    if (sourcePartyIdx < 0 || sav.PartyCount > 1)
+                    var sourceResolved = ResolveSlot(source);
+                    bool isParty = sourceResolved is { IsParty: true };
+                    if (!isParty || sav.PartyCount > 1)
                         ClearSlot(source);
                 }
                 break;
@@ -232,8 +308,9 @@ private void PerformSlotOperation(SlotModel source, SlotModel dest, DropModifier
                 if (destIsEmpty)
                 {
                     // Don't clear source if it's the last party member
-                    int sourcePartyIdx = _editor.PartySlots.IndexOf(source);
-                    if (sourcePartyIdx < 0 || sav.PartyCount > 1)
+                    var sourceResolved = ResolveSlot(source);
+                    bool isParty = sourceResolved is { IsParty: true };
+                    if (!isParty || sav.PartyCount > 1)
                         ClearSlot(source);
                 }
                 else
@@ -245,6 +322,20 @@ private void PerformSlotOperation(SlotModel source, SlotModel dest, DropModifier
         }
 
         _editor.ReloadSlots();
+        // Refresh any box viewers that were involved
+        RefreshBoxViewers(source, dest);
+    }
+
+    /// <summary>
+    /// Refreshes box viewers whose slots were involved in a drag-drop operation.
+    /// </summary>
+    private void RefreshBoxViewers(SlotModel source, SlotModel dest)
+    {
+        foreach (var bv in _boxViewers)
+        {
+            if (bv.BoxSlots.Contains(source) || bv.BoxSlots.Contains(dest))
+                bv.RefreshBox();
+        }
     }
 
     /// <summary>
@@ -257,23 +348,23 @@ private void PerformSlotOperation(SlotModel source, SlotModel dest, DropModifier
         if (sav is null)
             return null;
 
-        int boxIndex = _editor.BoxSlots.IndexOf(slot);
-        if (boxIndex >= 0)
-        {
-            var existing = sav.GetBoxSlotAtIndex(_editor.CurrentBox, boxIndex);
-            if (existing is null) return null;
-            return new SAVEditorViewModel.SlotChangeEntry(_editor.CurrentBox, boxIndex, existing.DecryptedBoxData, false);
-        }
+        var resolved = ResolveSlot(slot);
+        if (resolved is null)
+            return null;
 
-        int partyIndex = _editor.PartySlots.IndexOf(slot);
-        if (partyIndex >= 0)
+        var r = resolved.Value;
+        if (r.IsParty)
         {
-            var existing = sav.GetPartySlotAtIndex(partyIndex);
+            var existing = sav.GetPartySlotAtIndex(r.Index);
             if (existing is null) return null;
-            return new SAVEditorViewModel.SlotChangeEntry(0, partyIndex, existing.DecryptedBoxData, true);
+            return new SAVEditorViewModel.SlotChangeEntry(0, r.Index, existing.DecryptedBoxData, true);
+        }
+        else
+        {
+            var existing = sav.GetBoxSlotAtIndex(r.Box, r.Index);
+            if (existing is null) return null;
+            return new SAVEditorViewModel.SlotChangeEntry(r.Box, r.Index, existing.DecryptedBoxData, false);
         }
-
-        return null;
     }
 
     /// <summary>
@@ -285,18 +376,15 @@ private void WriteSlot(SlotModel slot, PKM pk)
         if (sav is null)
             return;
 
-        int boxIndex = _editor.BoxSlots.IndexOf(slot);
-        if (boxIndex >= 0)
-        {
-            sav.SetBoxSlotAtIndex(pk, _editor.CurrentBox, boxIndex);
+        var resolved = ResolveSlot(slot);
+        if (resolved is null)
             return;
-        }
 
-        int partyIndex = _editor.PartySlots.IndexOf(slot);
-        if (partyIndex >= 0)
-        {
-            sav.SetPartySlotAtIndex(pk, partyIndex);
-        }
+        var r = resolved.Value;
+        if (r.IsParty)
+            sav.SetPartySlotAtIndex(pk, r.Index);
+        else
+            sav.SetBoxSlotAtIndex(pk, r.Box, r.Index);
     }
 
     /// <summary>
@@ -308,19 +396,20 @@ private void ClearSlot(SlotModel slot)
         if (sav is null)
             return;
 
-        int boxIndex = _editor.BoxSlots.IndexOf(slot);
-        if (boxIndex >= 0)
-        {
-            sav.SetBoxSlotAtIndex(sav.BlankPKM, _editor.CurrentBox, boxIndex);
+        var resolved = ResolveSlot(slot);
+        if (resolved is null)
             return;
-        }
 
-        int partyIndex = _editor.PartySlots.IndexOf(slot);
-        if (partyIndex >= 0)
+        var r = resolved.Value;
+        if (r.IsParty)
         {
             if (sav.PartyCount <= 1)
                 return;
-            sav.DeletePartySlot(partyIndex);
+            sav.DeletePartySlot(r.Index);
+        }
+        else
+        {
+            sav.SetBoxSlotAtIndex(sav.BlankPKM, r.Box, r.Index);
         }
     }
 }
diff --git a/PKHeX.Avalonia/ViewModels/MainWindowViewModel.cs b/PKHeX.Avalonia/ViewModels/MainWindowViewModel.cs
index 30ff66f4a..30833a11b 100644
--- a/PKHeX.Avalonia/ViewModels/MainWindowViewModel.cs
+++ b/PKHeX.Avalonia/ViewModels/MainWindowViewModel.cs
@@ -135,6 +135,11 @@ private void RefreshGameDataAfterLanguageChange()
     /// </summary>
     private PluginLoadResult? _pluginLoadResult;
 
+    /// <summary>
+    /// Plugin host that provides ISaveFileProvider to plugins.
+    /// </summary>
+    private AvaloniaPluginHost? _pluginHost;
+
     public MainWindowViewModel() : this(new AvaloniaDialogService())
     {
     }
@@ -168,15 +173,27 @@ public MainWindowViewModel(IDialogService dialogService)
     /// </summary>
     private void LoadPlugins()
     {
+        if (!App.Settings.Startup.PluginLoadEnable)
+            return;
+
         var pluginPath = Path.Combine(App.WorkingDirectory, "plugins");
         try
         {
-            _pluginLoadResult = PluginLoader.LoadPlugins<IPlugin>(pluginPath, Plugins, false);
+            _pluginLoadResult = PluginLoader.LoadPlugins<IPlugin>(pluginPath, Plugins, App.Settings.Startup.PluginLoadMerged);
+
+            // Create the plugin host that provides ISaveFileProvider to plugins
+            var blankSav = BlankSaveFile.Get(App.Settings.Startup.DefaultSaveVersion, null);
+            _pluginHost = new AvaloniaPluginHost(
+                blankSav,
+                () => SavEditor?.CurrentBox ?? 0,
+                () => SavEditor?.ReloadSlots()
+            );
+
             foreach (var plugin in Plugins.OrderBy(p => p.Priority))
             {
                 try
                 {
-                    plugin.Initialize(this);
+                    plugin.Initialize(_pluginHost, App.CurrentVersion);
                 }
                 catch (Exception ex)
                 {
@@ -353,6 +370,17 @@ private async Task DumpAllBoxesAsync()
         }
     }
 
+    /// <summary>
+    /// Loads the initial save file and entity from startup arguments.
+    /// Called by App.axaml.cs after the main window is shown.
+    /// </summary>
+    public void LoadInitialSave(SaveFile sav, PKM? entity, string path)
+    {
+        LoadSaveFile(sav, path);
+        if (entity is not null)
+            PkmEditor?.PopulateFields(entity);
+    }
+
     public async Task LoadFileAsync(string path)
     {
         if (_isLoading)
@@ -411,6 +439,9 @@ private void LoadSaveFile(SaveFile sav, string path)
         SavEditor?.LoadSaveFile(sav);
         PkmEditor?.Initialize(sav);
 
+        // Update the plugin host with the new save file
+        _pluginHost?.UpdateSaveFile(sav);
+
         App.Settings.Startup.LoadSaveFile(path);
 
         Title = $"PKHeX - {sav.GetType().Name} ({Path.GetFileName(path)})";
@@ -574,10 +605,14 @@ private void OpenBoxViewer()
 
         try
         {
+            var slotManager = SavEditor?.SlotManager;
             var vm = new BoxViewerViewModel(SaveFile, SavEditor?.CurrentBox ?? 0)
             {
                 SlotSelected = pk => PkmEditor?.PopulateFields(pk),
+                SlotManager = slotManager,
             };
+            slotManager?.RegisterBoxViewer(vm);
+
             var view = new BoxViewerView { DataContext = vm };
 
             var mainWindow = (Application.Current?.ApplicationLifetime as IClassicDesktopStyleApplicationLifetime)?.MainWindow;
@@ -585,7 +620,11 @@ private void OpenBoxViewer()
             {
                 view.Show(mainWindow); // non-modal
                 _openSubWindows.Add(view);
-                view.Closed += (_, _) => _openSubWindows.Remove(view);
+                view.Closed += (_, _) =>
+                {
+                    _openSubWindows.Remove(view);
+                    slotManager?.UnregisterBoxViewer(vm);
+                };
             }
         }
         catch (Exception ex)
diff --git a/PKHeX.Avalonia/ViewModels/Subforms/BoxViewerViewModel.cs b/PKHeX.Avalonia/ViewModels/Subforms/BoxViewerViewModel.cs
index f6c3a41a0..e62726bbf 100644
--- a/PKHeX.Avalonia/ViewModels/Subforms/BoxViewerViewModel.cs
+++ b/PKHeX.Avalonia/ViewModels/Subforms/BoxViewerViewModel.cs
@@ -30,6 +30,12 @@ public partial class BoxViewerViewModel : ObservableObject
     /// <summary>Callback invoked when a slot is clicked to view its PKM.</summary>
     public Action<PKM>? SlotSelected { get; set; }
 
+    /// <summary>
+    /// Shared <see cref="SlotChangeManager"/> from the main editor, enabling drag-and-drop
+    /// between the BoxViewer and the main SAV editor.
+    /// </summary>
+    public SlotChangeManager? SlotManager { get; set; }
+
     public BoxViewerViewModel(SaveFile sav, int initialBox = 0)
     {
         _sav = sav;
diff --git a/PKHeX.Avalonia/ViewModels/Subforms/FolderListViewModel.cs b/PKHeX.Avalonia/ViewModels/Subforms/FolderListViewModel.cs
index ed735bb75..4f5290052 100644
--- a/PKHeX.Avalonia/ViewModels/Subforms/FolderListViewModel.cs
+++ b/PKHeX.Avalonia/ViewModels/Subforms/FolderListViewModel.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.IO;
 using System.Linq;
@@ -73,10 +74,22 @@ public partial class FolderListViewModel : ObservableObject
 
     public string WindowTitle => "Save File Folder List";
 
+    /// <summary>
+    /// Callback invoked when the user requests to open a file from the Recent or Backup list.
+    /// The caller (MainWindowViewModel) should subscribe to this to load the selected file.
+    /// </summary>
+    public Action<string>? FileOpenRequested { get; set; }
+
+    /// <summary>
+    /// Set to true when a file has been opened (so the dialog can close).
+    /// </summary>
+    [ObservableProperty]
+    private bool _fileOpened;
+
     /// <summary>
     /// Creates the view model with the given folder paths and backup directory.
     /// </summary>
-    public FolderListViewModel(string[] folderPaths, string backupPath)
+    public FolderListViewModel(string[] folderPaths, string backupPath, IReadOnlyList<string>? recentlyLoaded = null)
     {
         foreach (var path in folderPaths)
         {
@@ -84,18 +97,31 @@ public FolderListViewModel(string[] folderPaths, string backupPath)
                 Folders.Add(new FolderEntry(Path.GetFileName(path), path));
         }
 
-        // Load recent files from common save locations
-        foreach (var folder in Folders)
+        // Load recent files from the settings RecentlyLoaded list (matching WinForms behavior)
+        if (recentlyLoaded is { Count: > 0 })
         {
-            if (!Directory.Exists(folder.FullPath))
-                continue;
-            try
+            foreach (var recentPath in recentlyLoaded)
             {
-                foreach (var file in Directory.EnumerateFiles(folder.FullPath, "*", SearchOption.TopDirectoryOnly).Take(50))
-                    RecentFiles.Add(new SaveFileEntry(file));
+                if (File.Exists(recentPath))
+                    RecentFiles.Add(new SaveFileEntry(recentPath));
+            }
+        }
+
+        // Also include files from folder paths if no recently loaded entries
+        if (RecentFiles.Count == 0)
+        {
+            foreach (var folder in Folders)
+            {
+                if (!Directory.Exists(folder.FullPath))
+                    continue;
+                try
+                {
+                    foreach (var file in Directory.EnumerateFiles(folder.FullPath, "*", SearchOption.TopDirectoryOnly).Take(50))
+                        RecentFiles.Add(new SaveFileEntry(file));
+                }
+                catch (UnauthorizedAccessException) { }
+                catch (IOException) { }
             }
-            catch (UnauthorizedAccessException) { }
-            catch (IOException) { }
         }
 
         // Load backup files
@@ -155,4 +181,18 @@ private void OpenFolder(FolderEntry? folder)
         }
         catch { /* ignore failures to open folder */ }
     }
+
+    /// <summary>
+    /// Opens the selected save file entry by invoking the <see cref="FileOpenRequested"/> callback.
+    /// Triggered by double-clicking a row in the Recent or Backup DataGrid.
+    /// </summary>
+    [RelayCommand]
+    private void OpenSaveFile(SaveFileEntry? entry)
+    {
+        if (entry is null || !File.Exists(entry.FilePath))
+            return;
+
+        FileOpenRequested?.Invoke(entry.FilePath);
+        FileOpened = true;
+    }
 }
diff --git a/PKHeX.Avalonia/ViewModels/Subforms/Misc4ViewModel.cs b/PKHeX.Avalonia/ViewModels/Subforms/Misc4ViewModel.cs
index adb68c8bb..41c6bd713 100644
--- a/PKHeX.Avalonia/ViewModels/Subforms/Misc4ViewModel.cs
+++ b/PKHeX.Avalonia/ViewModels/Subforms/Misc4ViewModel.cs
@@ -69,6 +69,7 @@ public WalkerCourseModel(int index, string name, bool unlocked)
 /// </summary>
 public partial class Misc4ViewModel : SaveEditorViewModelBase
 {
+    private readonly SAV4 _origin;
     private readonly SAV4 SAV4;
 
     // General
@@ -130,35 +131,36 @@ public partial class Misc4ViewModel : SaveEditorViewModelBase
 
     public Misc4ViewModel(SAV4 sav) : base(sav)
     {
-        SAV4 = sav;
-        Record = sav.Records;
+        _origin = sav;
+        SAV4 = (SAV4)sav.Clone();
+        Record = SAV4.Records;
 
-        _maxCoins = (uint)sav.MaxCoins;
-        _coins = Math.Clamp(sav.Coin, 0, _maxCoins);
-        _bp = Math.Clamp(sav.BP, 0, 9999);
+        _maxCoins = (uint)SAV4.MaxCoins;
+        _coins = Math.Clamp(SAV4.Coin, 0, _maxCoins);
+        _bp = Math.Clamp(SAV4.BP, 0, 9999);
 
         PoketchAppNames = GameInfo.Strings.poketchapps;
 
         // Fly destinations
-        var locations = sav is SAV4Sinnoh ? LocationIDsSinnoh : LocationIDsHGSS;
-        var flags = sav is SAV4Sinnoh ? FlyWorkFlagSinnoh : FlyWorkFlagHGSS;
+        var locations = SAV4 is SAV4Sinnoh ? LocationIDsSinnoh : LocationIDsHGSS;
+        var flags = SAV4 is SAV4Sinnoh ? FlyWorkFlagSinnoh : FlyWorkFlagHGSS;
         for (int i = 0; i < locations.Length; i++)
         {
             var flagIndex = FlyFlagStart + flags[i];
-            var state = sav.GetEventFlag(flagIndex);
+            var state = SAV4.GetEventFlag(flagIndex);
             var locationID = locations[i];
             var name = GameInfo.Strings.Gen4.Met0[locationID];
             FlyDestinations.Add(new FlyDestModel(flagIndex, name, state));
         }
 
         // Sinnoh-specific
-        ShowPoketch = sav is SAV4Sinnoh;
-        ShowUGFlags = sav is SAV4Sinnoh;
-        ShowWalker = sav is SAV4HGSS;
-        ShowPokeathlon = sav is SAV4HGSS;
-        ShowMap = sav is SAV4HGSS;
+        ShowPoketch = SAV4 is SAV4Sinnoh;
+        ShowUGFlags = SAV4 is SAV4Sinnoh;
+        ShowWalker = SAV4 is SAV4HGSS;
+        ShowPokeathlon = SAV4 is SAV4HGSS;
+        ShowMap = SAV4 is SAV4HGSS;
 
-        if (sav is SAV4Sinnoh sinnoh)
+        if (SAV4 is SAV4Sinnoh sinnoh)
         {
             _ugFlagsCaptured = Math.Clamp(sinnoh.UG_FlagsCaptured, 0, SAV4Sinnoh.UG_MAX);
 
@@ -170,7 +172,7 @@ public Misc4ViewModel(SAV4 sav) : base(sav)
             }
             _currentPoketchApp = sinnoh.CurrentPoketchApp;
         }
-        else if (sav is SAV4HGSS hgss)
+        else if (SAV4 is SAV4HGSS hgss)
         {
             // Walker
             ReadOnlySpan<string> walkerCourseNames = GameInfo.Sources.Strings.walkercourses;
@@ -275,7 +277,7 @@ private void Save()
         Record.SetRecord32(Record32Index, Record32Value);
         Record.EndAccess();
 
-        SAV.State.Edited = true;
+        _origin.CopyChangesFrom(SAV4);
         Modified = true;
     }
 }
diff --git a/PKHeX.Avalonia/ViewModels/Subforms/Misc5ViewModel.cs b/PKHeX.Avalonia/ViewModels/Subforms/Misc5ViewModel.cs
index 9532748a1..62a3fd7ae 100644
--- a/PKHeX.Avalonia/ViewModels/Subforms/Misc5ViewModel.cs
+++ b/PKHeX.Avalonia/ViewModels/Subforms/Misc5ViewModel.cs
@@ -72,6 +72,7 @@ public PropModel(int index, string name, bool obtained)
 /// </summary>
 public partial class Misc5ViewModel : SaveEditorViewModelBase
 {
+    private readonly SAV5 _origin;
     private readonly SAV5 SAV5;
     private readonly BattleSubway5 Subway;
     private readonly BattleSubwayPlay5 SubwayPlay;
@@ -141,10 +142,11 @@ public partial class Misc5ViewModel : SaveEditorViewModelBase
 
     public Misc5ViewModel(SAV5 sav) : base(sav)
     {
-        SAV5 = sav;
-        Subway = sav.BattleSubway;
-        SubwayPlay = sav.BattleSubwayPlay;
-        Record = sav.Records;
+        _origin = sav;
+        SAV5 = (SAV5)sav.Clone();
+        Subway = SAV5.BattleSubway;
+        SubwayPlay = SAV5.BattleSubwayPlay;
+        Record = SAV5.Records;
 
         ReadFly();
         ReadRoamer();
@@ -153,8 +155,8 @@ public Misc5ViewModel(SAV5 sav) : base(sav)
         ReadSubway();
         ReadRecords();
 
-        ShowRoamer = sav is SAV5BW;
-        ShowKeySystem = sav is SAV5B2W2;
+        ShowRoamer = SAV5 is SAV5BW;
+        ShowKeySystem = SAV5 is SAV5B2W2;
     }
 
     private void ReadFly()
@@ -321,7 +323,7 @@ private void Save()
         SaveSubway();
         SaveRecords();
 
-        SAV.State.Edited = true;
+        _origin.CopyChangesFrom(SAV5);
         Modified = true;
     }
 
diff --git a/PKHeX.Avalonia/ViewModels/Subforms/SAVSuperTrain6ViewModel.cs b/PKHeX.Avalonia/ViewModels/Subforms/SAVSuperTrain6ViewModel.cs
index 5fa38892f..14e062897 100644
--- a/PKHeX.Avalonia/ViewModels/Subforms/SAVSuperTrain6ViewModel.cs
+++ b/PKHeX.Avalonia/ViewModels/Subforms/SAVSuperTrain6ViewModel.cs
@@ -99,11 +99,12 @@ public SAVSuperTrain6ViewModel(SAV6 sav) : base(sav)
         SelectedStageIndex = 0;
     }
 
-    partial void OnSelectedStageIndexChanged(int value)
+    partial void OnSelectedStageIndexChanged(int oldValue, int newValue)
     {
-        if (value < 0)
-            return;
-        LoadStageRecord(value);
+        if (oldValue >= 0)
+            SaveStageRecord(oldValue);
+        if (newValue >= 0)
+            LoadStageRecord(newValue);
     }
 
     private void LoadStageRecord(int index)
diff --git a/PKHeX.Avalonia/ViewModels/Subforms/SimpleTrainerViewModel.cs b/PKHeX.Avalonia/ViewModels/Subforms/SimpleTrainerViewModel.cs
index 081837038..4d1e0cb35 100644
--- a/PKHeX.Avalonia/ViewModels/Subforms/SimpleTrainerViewModel.cs
+++ b/PKHeX.Avalonia/ViewModels/Subforms/SimpleTrainerViewModel.cs
@@ -11,6 +11,7 @@ namespace PKHeX.Avalonia.ViewModels.Subforms;
 /// </summary>
 public partial class SimpleTrainerViewModel : SaveEditorViewModelBase
 {
+    private readonly SaveFile _origin;
     private readonly SaveFile _clone;
 
     [ObservableProperty]
@@ -69,7 +70,8 @@ public partial class SimpleTrainerViewModel : SaveEditorViewModelBase
 
     public SimpleTrainerViewModel(SaveFile sav) : base(sav)
     {
-        _clone = sav;
+        _origin = sav;
+        _clone = (SaveFile)sav.Clone();
 
         MaxNameLength = sav.MaxStringLengthTrainer;
         MaxMoney = (uint)sav.MaxMoney;
@@ -142,6 +144,7 @@ private void Save()
         if (Badge8) badgeval |= 1 << 7;
 
         SetBadgeValue(sav, badgeval);
+        _origin.CopyChangesFrom(_clone);
         Modified = true;
     }
 
diff --git a/PKHeX.Avalonia/Views/SlotControl.axaml.cs b/PKHeX.Avalonia/Views/SlotControl.axaml.cs
index 4b3efbee0..18ec9d415 100644
--- a/PKHeX.Avalonia/Views/SlotControl.axaml.cs
+++ b/PKHeX.Avalonia/Views/SlotControl.axaml.cs
@@ -7,6 +7,7 @@
 using Avalonia.VisualTree;
 using PKHeX.Avalonia.Controls;
 using PKHeX.Avalonia.ViewModels;
+using PKHeX.Avalonia.ViewModels.Subforms;
 
 namespace PKHeX.Avalonia.Views;
 
@@ -168,18 +169,36 @@ private void OnDrop(object? sender, DragEventArgs e)
 
     /// <summary>
     /// Walks up the visual tree to find the <see cref="SAVEditorViewModel"/>.
+    /// Falls back to reaching it through <see cref="BoxViewerViewModel.SlotManager"/>
+    /// when the slot lives inside a BoxViewer window.
     /// </summary>
     private SAVEditorViewModel? FindSAVEditorViewModel()
     {
         var itemsControl = this.FindAncestorOfType<ItemsControl>();
-        return itemsControl?.DataContext as SAVEditorViewModel;
+        if (itemsControl?.DataContext is SAVEditorViewModel savVm)
+            return savVm;
+
+        // BoxViewer path: reach the main editor through the shared SlotChangeManager
+        if (itemsControl?.DataContext is BoxViewerViewModel boxVm)
+            return boxVm.SlotManager?.Editor;
+
+        return null;
     }
 
     /// <summary>
-    /// Finds the <see cref="SlotChangeManager"/> from the <see cref="SAVEditorViewModel"/>.
+    /// Finds the <see cref="SlotChangeManager"/> from either the <see cref="SAVEditorViewModel"/>
+    /// or a <see cref="BoxViewerViewModel"/> ancestor.
     /// </summary>
     private SlotChangeManager? FindSlotChangeManager()
     {
-        return FindSAVEditorViewModel()?.SlotManager;
+        var itemsControl = this.FindAncestorOfType<ItemsControl>();
+
+        if (itemsControl?.DataContext is SAVEditorViewModel savVm)
+            return savVm.SlotManager;
+
+        if (itemsControl?.DataContext is BoxViewerViewModel boxVm)
+            return boxVm.SlotManager;
+
+        return null;
     }
 }
diff --git a/PKHeX.Avalonia/Views/Subforms/FolderListView.axaml b/PKHeX.Avalonia/Views/Subforms/FolderListView.axaml
index 18f9e2081..4e2501fc7 100644
--- a/PKHeX.Avalonia/Views/Subforms/FolderListView.axaml
+++ b/PKHeX.Avalonia/Views/Subforms/FolderListView.axaml
@@ -47,11 +47,13 @@
             <!-- File tabs -->
             <TabControl Grid.Column="1" SelectedIndex="{Binding SelectedTabIndex}">
                 <TabItem Header="Recent">
-                    <DataGrid ItemsSource="{Binding FilteredRecentFiles}"
+                    <DataGrid x:Name="RecentGrid"
+                              ItemsSource="{Binding FilteredRecentFiles}"
                               AutoGenerateColumns="False"
                               IsReadOnly="True"
                               CanUserSortColumns="True"
-                              GridLinesVisibility="Horizontal">
+                              GridLinesVisibility="Horizontal"
+                              DoubleTapped="OnDataGridDoubleTapped">
                         <DataGrid.Columns>
                             <DataGridTextColumn Header="File Name" Binding="{Binding FileName}" Width="*" />
                             <DataGridTextColumn Header="Size" Binding="{Binding FileSize}" Width="100" />
@@ -60,11 +62,13 @@
                     </DataGrid>
                 </TabItem>
                 <TabItem Header="Backups">
-                    <DataGrid ItemsSource="{Binding FilteredBackupFiles}"
+                    <DataGrid x:Name="BackupGrid"
+                              ItemsSource="{Binding FilteredBackupFiles}"
                               AutoGenerateColumns="False"
                               IsReadOnly="True"
                               CanUserSortColumns="True"
-                              GridLinesVisibility="Horizontal">
+                              GridLinesVisibility="Horizontal"
+                              DoubleTapped="OnDataGridDoubleTapped">
                         <DataGrid.Columns>
                             <DataGridTextColumn Header="File Name" Binding="{Binding FileName}" Width="*" />
                             <DataGridTextColumn Header="Size" Binding="{Binding FileSize}" Width="100" />
diff --git a/PKHeX.Avalonia/Views/Subforms/FolderListView.axaml.cs b/PKHeX.Avalonia/Views/Subforms/FolderListView.axaml.cs
index 70cfabdb4..22da7c570 100644
--- a/PKHeX.Avalonia/Views/Subforms/FolderListView.axaml.cs
+++ b/PKHeX.Avalonia/Views/Subforms/FolderListView.axaml.cs
@@ -1,4 +1,7 @@
+using Avalonia.Controls;
+using Avalonia.Input;
 using Avalonia.Interactivity;
+using PKHeX.Avalonia.ViewModels.Subforms;
 
 namespace PKHeX.Avalonia.Views.Subforms;
 
@@ -13,4 +16,20 @@ private void OnCancelClick(object? sender, RoutedEventArgs e)
     {
         CloseWithResult(false);
     }
+
+    private void OnDataGridDoubleTapped(object? sender, TappedEventArgs e)
+    {
+        if (sender is not DataGrid grid)
+            return;
+        if (grid.SelectedItem is not SaveFileEntry entry)
+            return;
+        if (DataContext is not FolderListViewModel vm)
+            return;
+
+        vm.OpenSaveFileCommand.Execute(entry);
+
+        // Close the dialog after the file is opened
+        if (vm.FileOpened)
+            CloseWithResult(true);
+    }
 }
diff --git a/PKHeX.Avalonia/Views/Subforms/MemoryAmieView.axaml b/PKHeX.Avalonia/Views/Subforms/MemoryAmieView.axaml
index 61c0023ef..59e6b132c 100644
--- a/PKHeX.Avalonia/Views/Subforms/MemoryAmieView.axaml
+++ b/PKHeX.Avalonia/Views/Subforms/MemoryAmieView.axaml
@@ -79,7 +79,7 @@
                                            VerticalAlignment="Center" IsVisible="{Binding HasSociability}"
                                            FontWeight="SemiBold" FontSize="11" />
                                 <NumericUpDown Grid.Row="6" Grid.Column="1" Value="{Binding Sociability}"
-                                               Minimum="0" Maximum="255" Width="120" Height="25" HorizontalAlignment="Left"
+                                               Minimum="0" Maximum="4294967295" Width="120" Height="25" HorizontalAlignment="Left"
                                                IsVisible="{Binding HasSociability}" />
                             </Grid>
                         </StackPanel>