Alright @faeran... so I can put this to bed and prevent anyone else spending time on it, I finally got it to work. Figured I'd provide the steps I took in case anyone else wants to achieve the same...
In the 'TextFiltersView.xaml' file, I replaced lines 527 - 560 (code block labelled 'Game Box') with the following:
<Grid x:Name="SelectedItemVideo1" HorizontalAlignment="Left" VerticalAlignment="Top" Visibility="Visible" Width="{Binding ElementName=Canvas,Path=ActualWidth,Converter={StaticResource ScalePropertyValueD},ConverterParameter=W;486.66666666666663;2560}" Height="{Binding ElementName=Canvas,Path=ActualHeight,Converter={StaticResource ScalePropertyValueD},ConverterParameter=H;846.6666666666666;1440}" RenderTransformOrigin="0.5,0.5" Panel.ZIndex="40" >
<TextBlock x:Name="SelectedItemVideo1imgfound" Text="{Binding ElementName=SelectedItemVideo1video, Path=HasVideo}" Visibility="Collapsed"/>
<transitions:TransitionPresenter x:Name="SelectedItemVideo1video" TransitionSelector="{Binding ImageVideoTransitionSelector}" StretchVideo="False" IsContentVideo="True" Opacity="1.0" RenderTransformOrigin=".5,.5" >
<transitions:TransitionPresenter.Style>
<Style TargetType="transitions:TransitionPresenter">
<Setter Property="Content" Value="{Binding ImageVideoView}"/>
<Style.Triggers>
<DataTrigger Binding="{Binding ElementName=SelectedItemVideo1,Path=Visibility}" Value="Collapsed">
<Setter Property="Content" Value=""/>
</DataTrigger>
<DataTrigger Binding="{Binding ElementName=SelectedItemVideo1,Path=Opacity}" Value="0">
<Setter Property="Content" Value=""/>
</DataTrigger>
</Style.Triggers>
</Style>
</transitions:TransitionPresenter.Style>
<transitions:TransitionPresenter.RenderTransform>
<TransformGroup>
<RotateTransform Angle="0" />
<ScaleTransform ScaleX="1.25" ScaleY="1.25" />
<SkewTransform AngleX="0" AngleY="0" />
</TransformGroup>
</transitions:TransitionPresenter.RenderTransform>
</transitions:TransitionPresenter >
<Grid.RenderTransform>
<TransformGroup>
<SkewTransform AngleX="0" AngleY="0"/>
<RotateTransform Angle="0"/>
<TranslateTransform X="{Binding ElementName=Canvas,Path=ActualWidth,Converter={StaticResource ScalePropertyValueD},ConverterParameter=X;110;2560}" Y="{Binding ElementName=Canvas,Path=ActualHeight,Converter={StaticResource ScalePropertyValueD},ConverterParameter=Y;628;1440}" />
</TransformGroup>
</Grid.RenderTransform>
</Grid>
In the lines above I altered the position of it a bit so that it lived slightly lower in the view than before. I also attached a video of the final result (this time it being an actual live capture of Big Box running).
Thanks again for pointing me in the right direction, it was fun to learn some XML/GUI design and great interacting with someone on the LaunchBox team!
big-box-list-view_1.mp4