I'm speaking for myself and not for other OVers here. I also believe that this is an area where I do disagree with OVers who follow the Molinist or 'neo-Molinist' view.
My view is that the universe is by definition fully open. It is simply nonsensical to argue that the future of the universe as a whole is in any way truly predictable. The idea of knowing every possible future is incompatible with the basic idea of the openness of the universe. The real universe is of necessity open and stating that God knows all possibilities but just doesn't know which of those possibilities will become actualised seems to me like openness in name only.
I can appreciate the sentiment though. It is an attempt to justify God without conceding predestination but without also conceding some measure of impotence or lack of control on God's part. In this view, God's lack of knowledge of the actual future is replaced by his knowledge of all possibilities of the future. It's a substitute. But it suffers from some profound weaknesses:
1. The actual future, or rather the actual course of history, is relegated to merely one of many possibilities. This devalues our lives. Surely we are more than just some arbitrary possibility? Surely there is more purpose to our lives than this?
2. The assumption is that God needs to be some all powerful magnate, knowing everything and perhaps controlling everything, in order to be God. This is effectively the same presupposition as Calvinism, which just goes a step further by asserting that God controls everything. Calvinism is indeed logical in that sense. But I don't think we need to go down that road. God is the most godly being it is possible to be. If anyone is godly, God is. But godliness was never about being the most powerful being in the world. It was about humility. 'Not by might, not by power, but by my Spirit' says the Lord.' The point of the resurrection was to prove this principle. As Jesus said, if he had wanted to, he could easily enough have called upon 12 legions of angels to save him from crucifixion. In openness theology, at least the way I see it, we need a new view of God. Calvinists declaim open theists as making God like some ordinary human who doesn't know or control the future but I say that Calvinists make God out to be nothing more than a superhuman, everything that man in his pride dreams of being - having so much power, so much knowledge, so much control. In my view of openness, these concepts are thrown out of the window. The God I believe in is not like this at all and it is the Calvinists who are making God out to be a man. As I say, I appreciate the idea that Molinism tries to bring but I feel it is misguided and something more radical is required.