In the very least, something more rounded and ergonomic than a row of buttons, something that lays out the buttons in such a way that they are more easily reachable without moving or contorting your hand. Fewer buttons for the pinky, more buttons for the thumb, which is now pretty much only used to hit spacebar. Maybe a big analog stick that sits under your palm, so you can tilt your entire hand to move (IDK how how useful that would be, but you wanted me to imagine something), leaving your fingers free to perform other actions.
In the very least, something more rounded and ergonomic than a row of buttons, something that lays out the buttons in such a way that they are more easily reachable without moving or contorting your hand. Fewer buttons for the pinky, more buttons for the thumb, which is now pretty much only used to hit spacebar. Maybe a big analog stick that sits under your palm, so you can tilt your entire hand to move (IDK how how useful that would be, but you wanted me to imagine something), leaving your fingers free to perform other actions.