Universities/Colleges want to see enough competency to be confident that your student will graduate in their major. That's the reason for requirements for college admission. If they look closely, at your son's competency, they might be satisfied but few will. Most universities won't. A box needs to be checked, in a conventional way. If he takes the FL AP Exam and does well - when he's a senior - that would be a good idea. He will need to demonstrate current competency, as a Senior.