Just got a reply to a question I asked on realself from a craniofacial surgeon
"Your chin does appear too long, but it is because of the way the ramus, or vertical portion of your jaw, has formed. It appears that you may have a bit of an open bite on your x-ray. If so, a Lefort osteotomy and genioplasty would probably be needed to correct the problem. And yes, they would help with lip incompetence. Hope this helps, Dr. Hall"
That would indicate that the posterior intrusion+genioplasty plan is legit as a plan B. He didnt mention lower jaw surgery but it is still ambiguous because he said the ramus is a problem. Now that I think about the people who have open-bites that get just leforts without genioplasty dont really have drastic results.