Years ago I had the idea of doing what I think the OP is talking about. I hole sawed a socketless BB shell for the ST and DT. While I was setting up to saw the chain stay holes I began to question my plan. There's already some shell face deformation due to heat induced shrinkage with shells, of either filleted or lugged designs. When I saw the huge openings and thought about the tube's lack of stiffness, across the tube section, I suspected this plan would result in even more distortion after brazing. So I stopped my plan. I kept that shell as a "paperweight" for a long time. Now I can't find it so suspect I tossed it out. Andy