Free will and omniscience are incompatible. To maintain that God foreknows the future with total accuracy when people have complete freedom to reach their own independent decisions, involves one in performing mental gymnastics in order to try and explain what is logically impossible.
Here we disagree. While I agree that will is limited to some extent, there is no incompatibility between free will and omniscience, and no gymnastics required. Free will and predestination is another story.
A man is given three coloured counters and told to keep one of them. The choice he makes is totally free - he chooses red.
Before time began (however that is interpreted) God foresaw the choice of a red counter.
Logically therefore, the man could never choose any other colour but red, otherwise God's foreknowledge would be faulty. But the doesn't take away the fact that (in time) the man's choice was free. This is compatible free will.
However, if the man had chosen the green counter, and he could have, then
that is what God would have seen in His foreknowledge.
The reason that the will remains free is that
omniscience is an observational trait, exerting no influence on a man's decision.
Omnipotence is the trait that makes the changes.
Predestination and free will deals with the influence of God on a man's actions and is a totally different argument. I believe in predestination as a scriptural truth, and the relationship between it and our perceived free will is a mystery to me, and I suspect anyone else. What we can plainly say is that God is in the driving seat and doesn't have to react to any surprises we pull on him. His will WILL be done and His influence in changing, hardening and softening hearts is all over the Bible like a rash.