Register multiple voice command definition files with Cortana

Question

Is there any way to register multiple voice command definition files with Cortana UWP?

I have an application which responds to custom cortana commands. Since the number of commands my application will respond to is large, I would like to split them up into multiple VCD files. I would like my app to respond to different CommandPrefix's as specified in each of the VCD file.

Sample VCD file 1:

<CommandSet xml:lang="en-us" Name="CustomCommands">
    <CommandPrefix>Custom</CommandPrefix>
    <Example> Open Website </Example>

    <Command Name="CustomOpenWebsite">
    <Example> Open website </Example>          
    <ListenFor> Open website </ListenFor>
    <Feedback> Opening your website </Feedback>
    <Navigate/>          
    </Command>
</CommandSet>

Sample VCD file 2:

<CommandSet xml:lang="en-us" Name="ReportCommands">
    <CommandPrefix>My report</CommandPrefix> 
    <Example> Open Report </Example>

    <Command Name="OpenReport">
      <Example>[Can] [you] Open [the] report [please]</Example>
      <ListenFor> Open report </ListenFor>
      <Feedback> Opening your report </Feedback>
      <Navigate/>
    </Command>
<CommandSet>

I am registering both of these VCD files like this

StorageFile vcdReport = await Package.Current.InstalledLocation.GetFileAsync(@"ReportCommandDefinitions.xml");
StorageFile vcdCustom = await Package.Current.InstalledLocation.GetFileAsync(@"CustomCommandDefinitions.xml");

await VoiceCommandDefinitionManager.InstallCommandDefinitionsFromStorageFileAsync(vcdCustom);
await VoiceCommandDefinitionManager.InstallCommandDefinitionsFromStorageFileAsync(vcdReport);

However, this does not seem to work. Only one of the VCD files get registered and I am only able to use voice commands from one of them.