Conventional arguments about free will seems to be missing one fundamental aspect, which is the essentially non-existent nature of the future.
Albert Einstein admitted that his theory of relativity cannot handle the enigma of the now.
A particular point in time proceeds from the future to the present, and on to the past, in a way described in the historic McTaggart paper.
In this temporal procession, the future does not seem to exist in any sense, until it becomes the now.
The past is also non-existent, for sure, even allowing for the possibility of Bertrand Russell's five minutes hypothesis, which suggest that the universe came into existence five minutes ago, with all the relevant memories of the past.
Henri Bergson's concept of pure memory would complicate this argument, which would solidify the reality of the past if taken seriously, but the five minutes hypothesis is not a logical impossibility on the surface within the conventional worldview.
So much for the past. The future, on the other hand, is absolutely non-existent, or so it seems from the nature of the stream of consciousness. Any models of free will ignoring this remarkable asymmetry of time would be at best good for all practical purposes, but ultimately hollow.
The enigma of free will evidently equals that of time.