Yes Flerc, I know about the bone remodeling which you posted. The problem is, you must have great amount of correction and that correction must be maintained for a very long time in adults in order to start bone remodeling.
And why some curves progress and others don't? I think that 50° mark alone can't be taken into account because scoliosis is 3D deformity. No matter what the cause of scoliosis is, we know that biomechanics have a major role in curve progression. Vertebral body stapling works for children who are still growing, that is clear evidence it is mainly biomechanical disease, also that means that bracing MUST work in children if we achieve high correction(check out Rahmouni from Germany, I have seen some amazing results on his web page with his overcorrective braces.)
You can't take into account just cobb angle, because vertebral rotation and spine's saggital profile also have influence on spine stability. Also, I think that vertebral bone density could influence progression. Maybe that is why females after menopause sometimes experience significant progression!?
If only gravity leads to curve progression, than body weight is also important because additional weight surelly puts more stress on the spine.
So, if adult scoliosis progression is influenced only by gravity and spine's ability to counter that force than we can say that all these components have influence: cobb angle, vertebral rotation, sagittal profile, body weight(BMI), bone density and also our posture. And yes, if ligaments hold vertebrae together, than loose ligaments and too much mobility is not good. This is so complex but it is all logical and makes sense. It just looks like medical comunity is not interested enough in this subject because they are now able to do these costly surgeries with acceptable outcome in most cases.
Spring, where the appex of your curve was, which vertebras were included in your lumbar scoliosis?