Preventing images from auto-cropping

I believe the issue we're experiencing is that the full-width image is preserving the same vertical height regardless of the screen width. While I appreciate that the image will load differently on a narrower screen, in my circumstance it would be better if the entire ratio of the image (vertical and horizontal) scaled to the width of the screen. This would make the full-width image taller on a wider screen, by necessity, but would keep any information from being cropped out. 

It feels like the current functionality is built around cosmetic stock images, like the ones in the asset library, that work perfectly fine when cropped away. While building a technically-focused learning module, however, I'm using the full-screen image block to include screen shots as examples where all edges of the image are important. Instead, I use Image Centered to make sure the entire image is viewable, but to see detail the learners will have to click to expand. 

An option in the Format options for the full width image block that locks the ratio would do exactly what I need.