The Steam Controller gets even closer to mimicking mouse movement 1:1 with a new update.
In the most recent Steam client beta update, released November 24, Valve added a new feature to the Steam Controller called ‘Mouse Region’. In short, this new trick makes it so you make touchpads behave more like a mouse.
Basically, it allows you to map the touchpad (or parts of it) to a certain region of a game window, like the ability bar in an action RPG or map in an RTS. Doing so will allow you to touch a certain part of pad and have the the mouse cursor move instantly to and from that region of the screen.
These regions can also be customised to allow for temporal configurations.
Currently, the feature is available only if you’re part of the Steam beta. If you’re not, you can simply opt-in through the client itself.