UMG: How to force aspect ratio?


I force an aspect ratio of 6:19 in my camera setup and I would like to make my UMG widgets to constraint to this aspect ratio, using letterboxing or whatever. Is it possible?

If aspect ratio is not contrained, then I see my widgets being draw partially over the letterbox space. I can solve this “manually” moving the widgets around and playing tricks with anchor points, but I guess there should be a more straightforward way of achieving this.