This isn't enough to be relevant to free will. You can construct massive impact by tying them to quantum systems, and one off things that happen occasionally g

This isn't enough to be relevant to free will. You can construct massive impact by tying them to quantum systems, and one off things that happen occasionally given the length of a lifetime. But the quantum effects that are needed for free will need to be continuous. We can build a system where QM decides if a nerve cell fires or not, but that is very different from QM being involving in determine if every (or most, or even 1%) of nerve cells firing. (And even if QM did factor in normally, that just reduces it from determinism to random chance, "free will" still doesn't show up. That's like arguing an AI with sufficiently well implemented RNG is necessary to be conscious.)