Mirror mode without black borders?

We want to display what the user sees through the HMD on a screen but at 16:9 rather than the 1:1 or whatever it is in the HMD. We can do this with the Rift but not the Vive. Am I missing a command?

Also interested if anyone has an answer !

r.setres 1920x1080 is not working aswell as the different mirror modes

EDIT : Blueprint way of doing it would be ace !

https://github.com/EpicGames/UnrealEngine/pull/2972

What is this? I don’t see any download links.