Nipple sparing mastectomy for BRCA mutation is becoming increasingly in demand as women learn more about breast cancer prevention and treatment. Delay procedures are a tried-and-true method to minimize soft tissue loss during elective and reconstructive procedures. Either a breast surgeon or a plastic surgeon can perform the delay procedure. Would recommend having your plastic surgeon and breast surgeon discuss scar placement so that you will have the best overall aesthetic result. Best to you.
Nipple sparing mastectomy is now being performed more often, but only minority of breast cancer patients are a candidate, depending on size, type and location of the cancer. Not every patient needs a delay procedure, but a delay procedure can improve the nipple survival if your reconstructive surgeon believes you may be at risk for nipple necrosis. I believe both surgeons are qualified to perform the procedure, but I would think that the surgeon performing the reconstruction would want to be involved since he or she will be working with the nipple aerolar complex during the reconstruction phase.