Now its up to you guys to decide the twist- I have a couple in mind-
-Redemption Island-
It gives the active players a better chance to stay in the game which is more fair then inactive players getting to the end. Strategy would be thrown off if everyone was active and self-votes were small.
-Exile Island-
We've had Exile Island before, but it would become an even more valuable place to be. Things like idols, being safe at tribal may not be the case anymore if you are on exile.
-Immunity idols/necklaces with special powers-
It could be anything from idols being used for you or against you, idols that can only be played for someone else, or necklaces that demand you to pick one other person to be immune from the vote.
-Tribe Switches-
The series has explored switches before in both Caribbean and Kenya but not as much as it could be used in Survivor: Costa Rica. Much like Gabon, tribe switches would become more often then they already are.