Apply scale outside of animation

[dkaszews]

Reading the documentation, I cannot see a way to window's scale outside of an animation. I would like to be able to change window scaling permanently, e.g. to make unfocused windows slightly smaller. I tried to do it using a zoom shader but it unfortunately does not work that well, as it creates a transparent border around the window, since it is still considered full size when calculating things like rounded corners or shadows:

Since there already seems to be an infrastructure for scaling during an animation, I hope this feature is not that hard to implement, though of course it might interact oddly with other pieces of code (such as window size matchers).