Comando de ligação no controle infantil?

Eu tenho um UserControl que é usado como "modelo" para caixas de diálogo de janela. Ele contém um botão Fechar e um botão Cancelar.

<UserControl x:Class="TombLib.WPF.Controls.WindowControlButtons"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:TombLib.WPF.Controls"
             mc:Ignorable="d"
             xmlns:darkUI="clr-namespace:DarkUI.WPF;assembly=DarkUI.WPF"
             xmlns:vm="clr-namespace:TombLib.WPF.ViewModels"
             xmlns:sg="clr-namespace:SpacedGridControl;assembly=SpacedGridControl"
             d:DesignHeight="100" d:DesignWidth="300"
             x:Name="root">
    <StackPanel VerticalAlignment="Center" HorizontalAlignment="Right" Height="Auto" Orientation="Horizontal">
        <Button Name="oKButton" Margin="{x:Static darkUI:Defaults.MediumThickness}" Width="100" Height="Auto" Command="{Binding Close}" CommandParameter="{Binding Window}" Content="OK"></Button>
        <Button Name="cancelButton" Margin="{x:Static darkUI:Defaults.MediumThickness}" Width="100" Height="Auto" Command="{Binding Path=Cancel}" CommandParameter="{Binding Window}" Content="Cancel"></Button>
    </StackPanel>
</UserControl>

public partial class WindowControlButtons : UserControl
{
    public static readonly DependencyProperty CancelProperty =
        DependencyProperty.Register(
        nameof(Cancel),
        typeof(ICommand),
        typeof(WindowControlButtons),
        new PropertyMetadata(null));
    public ICommand Cancel
    {
        get { return (ICommand)GetValue(CancelProperty); }
        set { SetValue(CancelProperty, value); }
    }

    public static readonly DependencyProperty CloseProperty =
        DependencyProperty.Register(
        nameof(Close),
        typeof(ICommand),
        typeof(WindowControlButtons),
        new PropertyMetadata(null));
    public ICommand Close
    {
        get { return (ICommand)GetValue(CloseProperty); }
        set { SetValue(CloseProperty, value); }
    }

    public static readonly DependencyProperty WindowParameter =
        DependencyProperty.Register(
        nameof(Window),
        typeof(object),
        typeof(WindowControlButtons),
        new PropertyMetadata(null));
    public object? Window
    {
        get { return GetValue(WindowParameter); }
        set { SetValue(WindowParameter, value); }
    }


    public WindowControlButtons()
    {
        InitializeComponent();
    }
}

Quero usá-lo na seguinte janela:

<Window x:Class="TombLib.WPF.Windows.SelectIdWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:TombLib.WPF.Windows"
        mc:Ignorable="d"
        xmlns:ctrl="clr-namespace:TombLib.WPF.Controls"
        xmlns:vm="clr-namespace:TombLib.WPF.ViewModels"
        xmlns:sg="clr-namespace:SpacedGridControl;assembly=SpacedGridControl"
        xmlns:darkUI="clr-namespace:DarkUI.WPF;assembly=DarkUI.WPF"
        Title="SelectIdWindow" Height="100" Width="300"
        d:DataContext="{d:DesignInstance Type=vm:SelectIdViewModel }"
        x:Name="Self">
    <sg:SpacedGrid Margin="{x:Static darkUI:Defaults.MediumThickness}">
        <!-- REDACTED -->
        <ctrl:WindowControlButtons DataContext="{Binding ElementName=Self}" Window="{Binding ElementName=Self, Mode=OneWay}" Close="{Binding CloseCommand,Mode=OneWay}" Cancel="{Binding CancelCommand,Mode=OneWay}" Height="Auto" Width="Auto" Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2" HorizontalAlignment="Right"/>
    </sg:SpacedGrid>
</Window>

public partial class SelectIdWindow : Window
{
    public ICommand? CloseCommand { get; set; }
    public ICommand? CancelCommand { get; set; }
    public SelectIdWindow()
    {
        CloseCommand = new WindowCloseCommand();
        InitializeComponent();
    }
}

public class SelectIdViewModel
{
    public string RequestedId { get; set; } = string.Empty;
    public IEnumerable<string> TakenIds { get; set;}
    public SelectIdViewModel(IEnumerable<string> takenIDs) {
        TakenIds = takenIDs;
    }
}

Porém, quando abro a janela da seguinte maneira:

SelectIdWindow w = new SelectIdWindow();
var takenIDs = Entities.Select(kv => kv.Key.Name);
w.DataContext = new SelectIdViewModel(takenIDs);
w.ShowDialog();

Recebo os seguintes erros durante a vinculação de WindowControlButtons:

É DataContextexplicitamente definido Selfcomo deve representar a janela, não o ViewModel. O que estou fazendo de errado aqui?