Flattening is definitely a problem when applying a sharpening filter to an image, for example the 2011 Blu-ray has such severe sharpening that blurred background elements become as sharp as foreground elements.

This shouldn’t be a problem with the technique I’m describing, since it SHOULD increase the sharpness of all parts of the image equally, rather than sharpening blurry areas only. The reason it should do this is because it is the focus of the lens which creates the illusion of depth of field, and more accurately pinpointing the photons actually preserves innate blurriness where the lens is out of focus. A basic super resolution technique of averaging several sequential frames may cause a loss of depth of field due to a slight softening of the parts of the image which are in focus, especially if these areas are in motion. I have described earlier how sharp edges can be blurred through frame averaging.