Feature Request: Opacity setting for in-game controls

I posted this in one of the suggestion threads some days ago, but I thought I'd give it its own thread.

I'd love to be able to change the opacity of the in-game controls, much in the same way it's possible to change the opacity for the overlay mini-map. Having played for some time now I know by heart where the controls are, so it'd be more than enough to just see a see-through version of them, and in turn get a bit of screen real estate back since you'd be able to see a bit more of your surroundings if the controls were see-through.