Hello 🙂. Also sorry to see you here, just like all of us.
I was also diagnosed with multifocal bca, with 2 lumps in my right breast, and another in my left. Post op pathology showed a third tiny lump was in between the two in rightie, as well as DCIS in both. Lucky I had a double mastectomy and it was all cleared. I kept both nipples initially and got expanders, but later left nipple went too due to DCIS. I think you should insist on a double if you feel safer that way. Lots of women have had both reconstructed in the same surgery. It makes more sense. Lots of lumps can’t be seen in any imaging tests, but they are there. And you had multiple in one breast, just like me, so it might be safer to remove both and have peace of mind.