After doing a large amount of research, I feel fairly confident saying that high-dose Potassium supplementation was the initial trigger that pushed me into two-year nightmare struggle with migraines which I am still dealing with. I didn't do anything beyond the recommendations that you can find on gwern's page and gwern doesn't really recomend anything that is technically unsafe, but the fact is that (apparently!) some people are migraine prone and these people should probably definitely not do what I did. (To be clear, I'm not blaming gwern in any way, that's merely a "community reference" that a lot of folks refer to.)