Yes, more, everyone wants more options, and Swen has said in interviews that there will be more.
That said, I wouldn't think a slider would be as feasible since these are images taken from irl faces specifically because they felt each of those faces brought something unique. That and they haven't done sliders in the past.
When sliders are used, it's necessary to make the textures less detailed in order to prevent the stretching from being obvious.
