If God knows everything by the brute fact of his essence, including the free acts of created agents, one has to wonder how and when such knowledge came to be. If God's omniscience is essential, rather than observational, then it would have existed as "long as" his essence has. Why not? On EO, he doesn't rely upon "waiting" for history to unfold or for agents to decide their choices--he "already" knows all by virtue of the brute fact of omniscience founded in his essence.
God's essence is eternal (i.e., without time rather than long-lasting). God is not developing, he doesn't gain some aspect of his essence (such as omniscience if that is the case) by means of time passing or by the instantiation of creation. That would make God essentially dependent upon something other than himself and breach aseity. So if God's knowing is by virtue of his essence, it means he always knew what he knows.
But if God knows every thought, every inclination, every action of every agent from all eternity, those acts and inclinations would have to be God's rather than the agent's. If EO is the case, then each and every one of those actually existed in God's essence quite apart from ever coming into being in the creature. How then could those acts and intentions ever be proven or understood to be anything other than a projection of God's own essence? They cannot.
We cannot have our cake and eat it too. We cannot say that God is not the author of intentions and acts (particularly sin) that were ultimately "in" him before they were in others. If God had in his mind the evil acts of devil and man before the devil and man had a mind, then that evil finds its genesis in God--he had evil in his heart before any of us had a heart that could be evil. If EO were true of God, we would have evil in us because God has evil in him and evil would, in fact, be God's will.
Determinism, Compatibilism, Molinism and Essential Omniscience all fail in this same way.
The interplay of omniscience and freewill can never be posited to be such that free actions were settled or known certainly in the mind of God before creation. Any attempt to do so hits this same brick wall, which has God very specifically and extensively knowing evil before evil was. If evil acts were known by God by virtue of his essence eternally, then in his essence God contemplated evil and plumbed the depths of temptation and enticement apart from their existence in creation. Therefore, permutations of Simple Foreknowledge which resort to omniscience by brute fact of God's essence fail God's scriptural disclaimer that sinful acts in general (James 1:13-15), and certain sinful acts specifically (Jeremiah 19:4-5), were founded in the hearts of sinners and not at all in God.
The only way I can see to avoid this error is to align with the scriptural accounts of God in action and the biblical instances of his self-disclosure and attribute God's omniscience (at least insofar as creaturely freedom goes) to Omnitemporal Observation. Regardless of how philosophically distasteful it may be, any of the more philosophically palatable theories fail to keep God from being the source of evil. Scripture demands that sinful intentions and sinful deeds not be attributed to God--not in conception, not in practice, and not first in the heart of God before in the hearts of our countrymen.
God doesn't think evil thoughts, how would he preconceive them for others? It seems to me that even omniscience has its limits!