I can't say if they would ever add this feature or not. Why do you want to would be the better question? The Polaris cards are very different to the Vegas that commonly undervolt to improve stability. The Polaris chips actually typically benefit stability wise from a Power Ceiling increase. Now if you are not gaming and and are achieving a desired computation speed you might just play with limiting your clock speed and this will decrease voltage as voltage is applied dynamically to begin with.
