The path of atoms are not responsible for the determination of will. The buffer between individual atoms and who cares is great, and interchangeable based on the comforts of the willful.
Quantum uncertainty is the sieve of consciousness. Quantum uncertainty isn't just wavy lines, as a technology it is domain and potential and constructive/destructive interference. The hyperdimensionality of super-amplitudes is confused with uncertainty. As a technology, the quantum scope is an echo chamber that holographically renders all inputs simultaneously. This holographic simulation is a feedback sense. All of this technology may be developed by the willful mind and reshaped for its own end.
I have no doubt one could not begin seeing these patterns before they are suggested (how many lifetimes of grunts before we spoke plainly?), so ignorance and information are without doubt consequential.
Quantum uncertainty is not presently understood. It is more practical to say there is a super amplitude which may be "sussed" (against your every postulated rule that it cannot be.) you will see there is more information capacity than spin dispositions and the qubit will dead end.
True free will is that you can decide (or not) right now without cohersion, it doesn't mean everyone is good at it, not creatures of habit, or not easily tooled.
Having an illusionary singularity (singularium?) in your mind juggling decisions is a mental technology. Our mental technology is not all alike.
Will is the determination of resolve. The cost and consequences of our determination to resolve is something we all pay dearly for our entire lives .
If the physical universe - matter and the laws of physics - is all that exists, then all you can be is matter that obeys the laws of physics. You're atoms that obey the laws of atomic physics, making up biochemicals that obey the laws of biochemistry, making up neurons that obey the laws of neurology. There's no room there for you to have free will. There is no way for you to make a non-determined choice. Worse, there's no room there for you to be a person. You're just a very complicated machine, and nothing more.
Yes, there is quantum uncertainty at the lower levels of this machinery. That doesn't give you free will, though, because you don't control the quantum uncertainty. It controls you (or at least your atoms, to some degree).
Yes, I know, compatibilism. That makes free will and physical determinism compatible by making "free will" into something less than what I think true free will is.
So, no, true free will is not possible - if the physical universe is all there is. Neither is true personality possible.