Florida
Cost-of-attendance cap
Florida Bright Futures + Benacquisto + National Merit are explicitly designed to stack to cost of attendance for Florida-resident National Merit Scholars. UF-administered merit awards (Presidential ladder, Florida Merit Scholarships) layer on top. Outside private scholarships count as a financial resource and replace 'self-help' aid (loans, work-study) before reducing UF or state grants.
Florida only cuts institutional aid when the COA ceiling is hit. That ceiling means stacking is upside until total aid approaches COA.
admissions.ufl.edu lists Florida Bright Futures — Florida Academic Scholars as the baseline automatic award that any outside scholarship will sit on top of.