i would rent a room at brickell bay for the day, store luggage, shower before departing.
brickell bay, cross the street and walk between the hyatt and occidental for beach access, very close...
full day at the beach.
First, one does not need a hassle after having a nice vacation in "Paradise." That being said, obviously, there were so many good suggestions from concerned "Forum Members," including our splendid monitors, Andrea and Lisa; that you have a lot of possible options.
I don't know "Bully," but from all the glowing reports on this Forum, he is truly a gem and is well liked and respected. If possible, I believe he would help in any way he can do so.
Welcome to the Forum. You did the right thing asking for help and suggestions.
When travelling as far as from Norway I decided I needed to take a 3 weeks vacation...
19 days in the warm sun and sea of Aruba - great snorkeling! - and many friendly people made up a really relaxing vacation
And that wonderful man "Bully" - who is very far from a bully! - was very helpful and took care of our baggage problems and proved to be a perfect and very reliable taxidriver So we could just relax and enjoy our last day as well. THANKS!