Surgeries like genioplasty and chin wing can be performed on anyone, as long as the nerves running through the chin/jaw don't run through the area that the surgeon needs to cut into.
But I'm actually really unsure what doctors can do for patients for patients with perfect bites who ask for bimax surgery to "just" get a bigger and better jawline.
The examples shown online always feature patients with extreme or moderate over- or underbites in combination with crooked teeth, but a lot of people don't suffer from those things or don't care about straight teeth but just want more chin and jaw.
My best guess is that surgeons simply move your upper and lower jaw forward and downward to make your jaw more protruding, but I'm not really sure.
I'm actually in the same situation, so I also really want to know.