BMX-after lumpectomies - how reliable is pre -BMX SNB?

I would really appreciate your take on my situation. I was diagnosed with 3 cm high-grade+ comedonectosis DCIS, had two lumpectomies that removed about 9 cm of it total,  one margin is still focally positive. My surgeon offered a SNB with the first lumpectomy, but did not insist. After reading some papers that leaned toward not doing SNB for DCIS I called him and asked if it was OK not to do it. He said it's ok. After no clean margins, we agreed on MRI. MRI of the  breast that had surgeries was inconclusive, with two small suspicious nodules that may be malignant. The other breast also showed high signal when contrast was used, suspected cysts, but otherwise seemingly benign. RO and MO said that there is no sense to save the affected breast because almost half was already removed anyways. Second opinion at UCSF: reviewed all pathology  slides and MRI;   surgeon at UCSF suggested  a biopsy for the two suspected nodules, cleaning up the DCIS, and performing an  oncoplasty, but also was not against the mastectomy for the cancerous breast. All docs say that BMX is not medically need, and suggest UMX only. I was talking BMX without reconstruction, and my surgeon can do it, if It's my wish; he  scheduled it reluctantly for this week. My reasoning for BMX is that imaging is not effective in my case, future monitoring is torturous, I do not want hormonals if they do not upgrade me to IDC,  I do not want rads, and I want one good arm with unaffected lymph nodes, which is my right arm that I use for writing on the board every day for hours, and for other tasks, of course. I think that it will be more trauma to the chest, and I can possibly get  PMPS. I understand that lymphedema is also possible even with one lymph node removed. I think that I may end up with all these side effects even with UMX, although BMX is certainly more traumatic.

 Surgeon also said that lumpectomies messed up the lymph drainage patterns, and it's possible that he will remove up to 3 nodes on the cancerous breast. I asked about the breast that is considered to be healthy, and he said that he is not doing SNB there, because mapping is good only for the short period of time , the dye will be gone pretty quickly, and he would not be able to find these nodes  after mastectomy anyways (apparently, the nodes  are about 1 mm each). He said that there is no value in removing lymph nodes, and it's done mostly for the purpose of staging should the invasive cancer is found.

I'm afraid that after these two lumpectomies they will find cancerous cells in some nodes  that are first to drain lymph now, and miss possible mets in the ones that were working before the lumpectomies which occur in 5-10% of pur DCIS cases.  

I would really appreciate your opinion and grateful for sharing your experience: Was your LNB done after the lumpectomies?  How many nodes were removed?  What was the status of the nodes? Do you have the lymphedema on the healthy side as well,  or only on  the SNB side?

Thank you