In Ft. Lauderdale it's much more likely that you can make an 11 AM flight than most other ports of embarkation.
That said.. you have to make certain the guest relations desk knows of your early flight, to get you off in the first group leaving the ship. Then grab a taxi rather than waiting for transfers.
Only thing is, if the ship is delayed for some reason, you have to be prepared for the challenge of finding another flight should you miss it.
If you are willing to accept that responsibility, then go ahead and try for the early flight.