For me, scoliosis is strictly a structural problem. The fact that biological factors condition this structure doesn't invalidate that statement https://medium.com/@Flerc/scoliosis-the-unified-theory-9f1c9dbdc4db
If the stretched soft tissues on the convex side were shortened, the curve would reduce proportionally. I believe the only non-surgical way to achieve this would be by significantly strengthening that side, but I understand that this alone wouldn't be enough (or that swimming would correct curves). Those muscles would also have to exert the exact force (magnitud and direction) they would exert when fighting against gravity.
If the curve is very large and the spine is flexible, if, on the floor with feet against a wall, knees bent, and elastic bands across the shoulders and attached to the wall, the legs were extended, the force of gravity would be simulated. Would this exercise then shorten the muscles on the convex side?