I completely agree with you on 95% of what you're saying, but I think you're incorrectly applying the concept of time in what is really a dimensional dilemma. I'm sure you've drawn a 'cube' on a flat paper before. It is a 2D rendering that can give the impression of a 3D image. Have you ever noticed that it if you change your perspective a bit, you could flip the cube around? This is effectively a 'decision' made in the second dimension that is expressed in the third dimension. Just as the decisions we make in the third dimension, moment to moment, manifest themselves at later points in time (the fourth dimension). I don't really see a reason for time to be a necessary constraint for the capacity of decision. Theoretically, a decision by someone capable of omniscience of our own dimension would just be expressed in the dimension superior to their own existence.
ETA: To clarify, I don't actually believe free will exists. I think the discovery of each moment gives the impression of free will as we are constantly observing and evaluating, but it is even our own observations and evaluations that are being played out to us. I do think that this 'impression' of free will is a constant for any conscious being on any supposed plane.