I'm contemplating switching to a full B complex instead of ATP Cofactors, given B6 is also used in thyroid hormone production. And generally B's all need to go together to prevent relative depletions. It's one aspect of the Breast Cancer Choices Iodine protocol I'm debating whether it can be improved...
You mentioned you tweaked your B-vitamin intake. How much B2/B3 do you use at the 100mg level? ATP Co-factors says use 1 - 3 tablets which is a wide variance (500 - 1500mg of Niacin).