Does earning an agi freeze to he foi? If so what is the reg that covers this
After you get your AGI certificate, you never have to do the FOI written again, if that's what you mean (You will still be asked about FOI on the oral portion of your CFI checkride though).
But I’m all honesty the foi written was the easiest written of them all. Only 300 question bank. Wake up at 7 am and use Sheppard and then ace the test by noon