I don't think a tri-Omni being can itself have free will. If it is omniscient, it can foresee everything it will ever do. If it is omnipotent, it can do otherwise. But if it does otherwise, it was not actually omniscient to begin with. So an omniscient being can only do what it foresees it will do and does not possess free will in any meaningful sense, it can't choose to do other than what it already knows it will do. In effect, all its choices were made instantaneously as soon as it came into existence and can never be changed.
I'm not anti-Christian. I'm anti-stupid.
