No FAFSA is required for Miami’s merit scholarships. If you do the FAFSA, the merit aid shows up as the “Redhawk Excellence Scholarship” when your financial aid letter arrives in the spring and goes toward meeting the gap between your EFC and MU’s COA.
Great question about the senior year first semester grades bumping the GPA over 3.5. I would email the admissions officer assigned to your son to see if that could be taken into consideration. If the answer is “yes”, it would be nice to have it in writing in case the resulting merit aid offer is not consistent with the merit aid chart.