Intensity 4k output for non-broadcast standard resolutions

Is there anyway that the Intensity 4k can output non-broadcast resolutions without stretching or squishing them to fit the whole screen? For instance in After Effects we work in a lot of top and bottom cropped footage so we might have a comp resolution of something like 1920x800. The Intensity will take this resolution and stretch it to a 1920x1080 frame but it would be nice if it didn't do any resizing so we can view a correctly letterboxed version on the external monitor. The basic resizing options in Desktop Video don't do what I need it to do.

I had a Matrox card previously which did exactly this, it was far better to use in AE but of course Blackmagic force you into buying their hardware for use with Resolve.