I suffer migraines for years as my mother and in addition I’m epileptic.
The first time I used Cefaly, I was worried that I might have a seizure because it is such a strange sensation, but I was fine.
I have done number 1 when I had a migraine (I think you have to be quite brave to do this) and it did work, amazingly, the pain went.
To prevent I tend to do either the number 2 mode or number 3 mode once per day (I like number 3 mode, it definitely puts me in a better mood!).