When should I start the B12 as my coenzymes yet likely high enough?

Plenty of people still benefit from the methylcobalamin before Flavin Adenine Dinucleotide and Flavin Mononucleotide are optimized.

Once you’ve been taking all 3 minerals and the B2 together, then you can introduce B12. That’s what I generally recommend.

If you’re having trouble getting used to the minerals and you’re still having reactions from them, then I recommend going slower and waiting longer. And then introduce the B12 once you’re more settled with the minerals.