‘So as long as he takes one AP science course each year for the next two years, does it matter that he’s not doubling up’
no , BUT I think hes making a BIG mistake trying to take 2 intense science AP classes his JR year, and a relatively “whimpy” science AP his SR year.
he would be better off taking either AP Bio OR Physics his Jr year, so his GPA does not go in the toilet, and the other AP his Sr year.
in other words, I agree with ucbalumnus.