This answer is highly opinionated so please take it with a grain of salt; I just thought I would be providing a different approach
I'd say you are looking at the wrong place especially from the perspective of the functionality and use of 'will', especially to the individual (as per existentialism). I would personally say your search is directed in the wrong way, I think it is much beneficial to look into psychology rather than physics. You can refer to the studies by Christopher Janaway on Schopenhauer’s notion of the unconscious will.
I personally think that the 'will' is more psychological rather than metaphysical.