BMI requirements can be overcome - there is no medical/scientific basis for restricting the DS to high BMI patients. If you qualify for bariatric surgery, you qualify for a DS - it is a standard of care procedure without limitation. It is beyond doubt that it is SUPERIOR to other bariatric surgeries for BMI > 50; that doesn’t mean there is any reason to limit it to higher BMIs.
As for revision, there is even less reason to limit it to BMI > 50; prior failed bariatric surgery indicates an even greater need for a metabolically effective procedure. Waiting until the inevitable regain to high BMI is ridiculous and scientifically unsupported, and medically indefensible.