While I am personally rooting for Dani, I think Jeff would be a fool not to put her on the block.
Dani is going to play POV if she is on the block or not. If Jeff decides to try to backdoor her, and Dani wins the POV, she will force Jeff to tip his hand to his own alliance, by forcing him to put one of his own on the block. However, if he simply puts Dani on the block, and she wins POV, he can put up either Porsche, or Kalia and keep his alliance in tact.
Thus far, I think Dani has shown to be the best "game player" in the house. That being said, Jeff has a big opportunity this week to enter that discussion. He has the alliance loyalty, and numbers, he simply needs to make the smart decision. The fact that he is considering backdooring Dani, so he doesn't have to offend her in case she wins Veto, shows how afraid of Dani he really is. But, like I say, if she is going to win she is going to win. The best "game move" imo, is put her straight up on the block. If he doesn't, Dani could stay and you bet your first born, she will break up JJ the first chance she gets.