I have a working <syncfusion:BackStateCommandButton ... in my Ribbon window. It is successfully bound via Command binding.
I would like to add a keyboard shortcut. Normally in WPF you use InputBindings
However, the follow is not bound in the WPF Backstage of the Ribbon
<syncfusion:BackStageCommandButton Header="Close" Command="{Binding CloseFileCommand}"
IsEnabled="{Binding DocumentsVisible}"
>
<syncfusion:BackStageCommandButton.InputBindings>
<KeyBinding Key="w" Modifiers="Ctrl" Command="{Binding CloseFileCommand}"/>
</syncfusion:BackStageCommandButton.InputBindings>