How much would could a sliding genioplasty improve my facial profile? (photos)

I was told on here that my chin is " horizontally short but vertically elongated as well " and that a chin implant wouldn't be a good idea because no chin implant can give me a horizontal projection more than 12mm, which wouldn't improve my face that much. Looking a photos of my chin from the side it seems further back than the photos I have seen of patients who have successfully had a sliding genioplasy, I'm curious as if I'm misinterpreting how much the procedure could more my chin forward.