Only the points at that resort can be used at the 11 month window, so only BWV points can be used to book at the 11 month window at BWV, you have to save the other points till the 7 month window to use them. I have 700 points, and believe me, it's still a challenge getting the points together to get the accommodations I want at the 11 month window. I try to alternate contracts and add-ons so I can do what I want.
Also, if you add on thru Disney, you must keep the same use year as your main contract. It's a lot easier that way, but you can get a different use year if you go resale. I would think twice about that. I have 3 separate contracts with add-ons, and it's always complicated when I make ressies at the 11 month window. If you normally book at the 7 month window, then you have really simplified things a lot. I have 110 point add on at BCV, and I just hate it--it's not enough, and it's not at BWV, where all my other points are. And with banking and borrowing, I really have to watch to make sure those points don't get lost in the shuffle.