What about having some bastard-prick like myself bringing out the 2-1-1 vote for the hell of it? If you were the immunity winner at F4 and everyone was going to vote out the obvious winner (say, Yau-Man), you could ask Yau-Man which of the other two he's voting for and then vote for the other person. Nobody would ever expect you to do as such. Strategically, it makes sense because then you can give the F4 bootee a pity vote by not writing one in their direction while also showing that the other three people that made it this far were all within one vote from being ousted, making the argument that you were the only one in control infallible.