This part is no longer true. Now, even if you're on campus, you only need to show a negative test to enter campus buildings. If you're just taking all online classes from your apartment, you might never need to get tested.
There's no testing protocol noncompliance issue with Miller hanging out in Miami for a few days. Just like there's no issue with Curbelo going to Puerto Rico, Kofi to Jamaica, or Da'Monte to Peoria. Upon return to campus, they'll need one to get into Ubben, but, until then, they're in compliance.