Early debarkation can be done by what is called "self-debarkation". This means you have to be able to handle ALL of your luggage with NO assistance and be be able to carry it off the ship. This is the first group called to leave the ship.
You likely would have no problem making an 11am flight from FLL. That is the earliest I'd go with. Now, people often post how they made a flight at 9am with time to spare. That is taking a huge risk. There are variables. The ship could be late arriving. Customs could have problems which delay debarkation (been there...twice). Do not ever assume that the ship will definitely arrive at the advertised time.