P: Crop to screen in Lightroom

I would like to see a feature that allows you to crop the screen exactly as you see it on your phone or desktop.

Maybe it is just me, I find it very difficult to judge a crop when there is extra space and icons around it. Currently the UI displays the portion of the original photo that has been cropped out, the degree controls and the straighten, flip and rotate controls. 

To me the boarder of the screen is much easier to use as an edge. I would like to be able to zoom in to how I want to frame the picture and thern tap the screen to set the crop.

NB I realise this will only work if you want to crop a photo to the ratio of a phone screen or monitor.