FlowDirection.RightToLeft does not apply to custom TitleBar or caption buttons

public sealed partial class MainWindow : Window
{
    const int GWLEXSTYLE = -20;
    const int WSEXLAYOUTRTL = 0x00400000;
    public MainWindow()
    {
        InitializeComponent();
        ExtendsContentIntoTitleBar = true;
        SetTitleBar(AppTitleBar);
        TitleBarPageWindowGrid.FlowDirection = FlowDirection.RightToLeft;
        UpdateCaptionButtonDirection(FlowDirection.RightToLeft);
    }
    [DllImport("user32.dll", EntryPoint = "SetWindowLongPtr")]
    internal static extern IntPtr SetWindowLongPtr(IntPtr hWnd, int nIndex, nint newProc);
    [DllImport("user32.dll", EntryPoint = "GetWindowLongPtr")]
    internal static extern IntPtr GetWindowLongPtr(IntPtr hWnd, int nIndex);
    private static nint GetWindowHandleForCurrentWindow(object target) =>
        WinRT.Interop.WindowNative.GetWindowHandle(target);
    private void UpdateCaptionButtonDirection(FlowDirection direction)
    {
        var hwnd = GetWindowHandleForCurrentWindow(this);
        if (hwnd != 0)
        {
            var exStyle = GetWindowLongPtr(hwnd, GWLEXSTYLE);
            if (direction == FlowDirection.RightToLeft)
            {
                exStyle |= WSEXLAYOUTRTL;
            }
            else
            {
                exStyle &= ~WSEXLAYOUTRTL;
            }
            SetWindowLongPtr(hwnd, GWL_EXSTYLE, exStyle);
        }
    }
}