Randomness (or whatever it is that we are talking about by using the word "random") is not necessarily "perfectly unpredictable," or at least we need to spell out that phrase "perfectly unpredictable" more closely. To the extent that randomness is (and isn't) caught up with chances/probabilities, we also have to keep in mind e.g. completely subjective interpretations of probability, which although licensing "crazy" beliefs like, "The PhilosophySE is secretly in control of the entire universe" (just so long as we consistently assign the relevant probabilities), nevertheless present us with yet another problem to solve, here.
Now the motive for believing in the indeterministic form of free will is often stated nowadays in terms of being a precondition for "moral responsibility." Between the two of them, Wilfrid Sellars and Harry Frankfurt have done a decent job of undermining such a preconditional statement, Sellars more on the internal psychological side of things (his reflection on "reactive attitudes") and Frankfurt on the external such side (the mesh issue). But when Kant argues for transcendental freedom (in the second Critique), he frames it much more simply in terms of the following line of reasoning:
- Suppose I am obligated to do X.
- If I am obligated to do X, I am able to do X to some extent.
- Sometimes I violate my obligations.
- Therefore, when I am under an obligation to X, I face a choice between Xing and not Xing.
This reference to a physical example of a "mere possibilia" is not a reference to complex attitudes, at least not on its surface. "If A, then B or not B," does not clearly have anything directly to do with randomness, chance, or even a dedicated faculty of willpower. And Kant, although a faculty psychologist par excellence, is at pains to locate transcendental freedom in transworld logical space, so that he says that we could empirically build a model of human behavior that genuinely explains and predicts all empirically visible human actions and which nevertheless comports with the modal spontaneity involved in deontic affairs.
I am sympathetic to a post-physicalism that equates electrons with the primary physical substrate of consciousness. Electrons have enough quirky aspects that I don't see why we would need to advert to more fantastical conceptions of "refined spiritual matter" such as e.g. the LDS Church tries to present as the constituents of our spirit. I recognize that quantum indeterminacy is not one-to-one with the indeterminism we are looking for with respect to transcendental free will (or choice; note e.g. Kant's distinction between Wille and Willkür), so I cannot say that electronic indeterminacy is indistinguishable from such freedom. Perhaps panpsychism is true and so electrons are conscious even just by themselves, rather than only in concert as sustained neurological activity. But until I see a reason to accept the axioms that go into controverting transcendental freedom (as deontic-modal disjunction) on grounds of "randomness" or the like, such criticisms, and the preoccupation with addressing them, won't seem compelling. Whether that reopens the door to thinking of electronic indeterminacy as sufficient in order to free choice, I can't say for now.
Addendum. I guess I would say that trying to equate free will with randomness, and defending or critiquing such will on that basis, is liable to be equivocal without a more refined sense of what randomness, chance, etc. are really supposed to be, but then even on its own terms just the same. "It was random that choice A was made instead of choice B," is not the same assertion as, "A occurred randomly." No one, not even I myself, can unfailingly predict what I will do with my freedom, but that does not mean that, once I have done something with it, that I was somehow not the author of what I did. If the human mind or spirit is largely reducible to electronic activity, even the activity of a single electron in the limit, perhaps there will be the intended overlap between quantum indeterminacy and broader modal indeterminacy, but the solution to this question is for another day.