Maybe you're seeing something that I'm not, in which case I'd appreciate it if you would enlighten me. It could also be that I haven't accurately expressed my intended meaning.Do you think he is conflating Foreknowledge with something like the Double Slit Experiment in Quantum Physics? That experiment says no one knows which way a Photon goes until it's Observed, so in a way the Observer causes the course of the Photons to be Certain. Wouldn't Certainty then be Necessary?
I don't see where anything in the OP or in the Edwards quote points toward God being in any way dependent upon creation. As for photons, God's knowing of which way they will go does not in itself cause them to go that way. God's control is not merely by knowing which way they will go, but by exerting His power in such a way, directly or indirectly, to effect the desired result. But just knowing the result does not in any way cause the result.