Hi and welcome!
Dr. Sudan is definitely an experienced DS surgeon. Someone else around here (sorry, I can't remember who it was) did post recently that the group at Duke is now making excessively long common channels in hopes of avoiding nutritional deficiencies. So if/when you see him, you need to ask about that, and make it very clear that you want not just the real DS with 2 anastomoses but also a cc of 100 cm or thereabouts. You are an intelligent, well informed patient who is capable of following directions and who understands that the protein, vitamin, and mineral requirements are exactly that, requirements, and that this is a life time commitment.
My guess is that they've had a few patients who have been noncompliant and gotten themselves into trouble, and they are a bit gun shy about the malabsosrption of the DS, which is serious malabsorption. But it's also the malabsorption that creates and esp helps maintain our weight loss and makes the DS the most effective bariatric surgery available. Accept no substitutes!