Random behavior of subatomic particles doesn't make free will any likelier either though.

If they act at random on a makro level their randomness would average out to zero. And that actually checks out, since the mechanical forces of the atomic and molecular level are known, observable, and provable. An apple drops from the tree to the ground, every time. Causality is still a thing, even if not observable at the subatomic level.

The only way to imagine a subatomically based free will would be some mechanic over which we, at will, could change the randomness of subatomic particles to behave in a predictable pattern and on a scale that's grand enough to make the proverbial apple fall upward. Or at least make or synapses do something that they physically speaking wouldn't have done otherwise.

Free will is as likely as magic. In fact it would actually be some form of magic - a volitional breach of causality itself.