That term "Free Will" tends to get thrown around quite a bit, with an expectation of guaranteed singular meaning and resonance (like the word 'love'). When I look closely at "Free Will", I find a compound statement.
Note: there are are a lot words that get thrown at me, which I see in a parallel sort of fashion - as compound words.
Example: the word 'For+Ever": (for = 'in the service of'... as in, "I did this for you) + (ever = 'time') = "In the service of time." Etymologically, 'ever' has ambiguous origins; yet, its use allows us to vector on its definition as 'time' - as in the case of 'however' = 'how time works', and also used as counterpoint (asserting duality); evermore = 'more time'; ever-after = 'time after some boundary condition'.
By such parallel meaning, two people could have a conversation and not even realize there is a encrypted parallel layer of conversation happening.
In one of these parallel triggering/scripting systems, I look at "Will' by it's use. What I find is a very workable substitute... the word "Script"... as in a linguistic construct, a perceptual pattern, computer code, behavioral command, and the lines an actor reads or memorizes to depict a 'character'. We can substitute "Script' in common uses of the word "Will":
"Thine script be done", "It is my script", and my favorite... "Do as thou art scripted shall be the whole of the law."
But then, what can we mean by "Free Script"?
Well, 'Free' is often vectored in the empirical consensus as: 'breaks script', 'wrong' script, 'contesting' script, even 'parallel script' (ha ha). In a parallel fashion I might also consider the 'Gluten Free' interpretation... "Absence"
So then, Free+Will = "Absence of Script." It's kind of like reading the spaces between the lines (there's nothing there, but the absence of script allows the jumping between tracks). One might say that the place Zach Bush's patients were talking about, the place they did not want to come back from, 'is' Free Will (Absence of Script).
Much has been said about 'stopping the internal dialogue'... maybe 'free will' is what is meant here too.