I can see what you mean, painz. Currently, there's no way to implement that, it'd take a major change in the win+right feature i added and i don't have that time.
You can, however, use the "restore" grid element, which does just that. You press it once, and it'll resize to the last size that window had, you press it again and it'll go back to the size it had before you restored. (it's represented as "last size" and is present in the "edge grid", for example).