Error trying to freeze a Rectangle filled with a BitmapCacheBrush - wpf

Question

I'm trying to Freeze a BitmapCacheBrush, but when I call Freeze it errors stating it can't be frozen.
What I'm trying to do is fill a Rectangle with a BitmapCacheBrush and then at some point, Freeze it so I can then animate the Rectangle and reuse the source Grid for something else (whilst animating the Rectangle).
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="50*"></RowDefinition>
<RowDefinition Height="50*"></RowDefinition>
</Grid.RowDefinitions>
<Grid x:Name="LISTING">
<Grid.CacheMode>
<BitmapCache RenderAtScale="1" SnapsToDevicePixels="True"/>
</Grid.CacheMode>
<Rectangle x:Name="Rectangle1" Fill="Red" />
<Label Content="Test" FontSize="20" Foreground="Black" />
<Button x:Name="Button1" Click="Button1_Click"/>
</Grid>
<Rectangle Grid.Row="1" x:Name="Rectangle2" >
<Rectangle.Fill>
<BitmapCacheBrush x:Name="BMCB" Target="{Binding ElementName=LISTING}"/>
</Rectangle.Fill>
</Rectangle>
</Grid>
In my test I am trying to see if I can Freeze the BMCB BitmapCacheBrush when the button is clicked, then as a test I want to hide the button and still see the bottom rectangle intact.
I'm wanting to use BitmapCacheBrush for the performance aspect.
Is this even possible?
Thanks
Ben

Answer 1

I would say No: But my only source to prove that is the Freezable documentation in the msdn, which says:
A Freezable can't be frozen if any of the following are true:
It has animated or data bound properties.
It has properties set by a dynamic resource.
It contains Freezable sub-objects that can't be frozen.
So i guess you can't freeze it because of your Target="{Binding ElementName=LISTING}" binding.