Exact measurement scale

Ideally, in mesh edit mode, you would press S to scale, and there would be a key bind at the bottom of the screen that toggles specific and normal scaling. in specific scaling you would enter the amount and axis as you normally would when scaling, but it would scale to exact measurements. I made a simple addon that uses a dialog box to accomplish this, but it would be better if integrated into the scale function. I can also see this being useful in other parts of blender where scale is used.