I know that from my experience in being a programmer that there can be no escape from the programmed logic within a computer program. But in the scenario you quote : "we weigh up the options to identify which possibility plays out best against our current set of inner values and preferences" - sometimes we do not bother weighing up the options .... we can just choose do something at will (then deal with the consequences, asking yourself "Why on earth did I do that?"). I think it would be labelled as impulsive behaviour, and we are all capable of doing it, because we have the freedom to do so. And it has nothing at all to do with randomness because it is a consciously driven act of will.
All this demonstrates, is that 'will' is often subliminal. But so what, nearly everything that goes on in a head is subliminal, conscious workspace is very limited. If you are racing to return a serve, do you stop and get your calculator out to start solving equations of motion ? No, our minds are solving complex problems all the time without our awareness of the calculation going on under the hood. If you date a woman, and you find you quite like her but can't quite put your finger on
why, again, there is complex subliminal calculations going on under the hood, the detail of which might not make it into conscious workspace, so we content ourselves with the observation that there is the right 'chemistry'.
When we make a choice, there must be some method of prioritisation going on, otherwise a decision will not be made. The extent to which this process is conscious or subliminal is irrelevant to the underlying principal of what a choice is. A choice has to be an outcome of a weighing up of priorities and options within a system of values. A choice that does not reflect the relative strengths of is relevant considerations is not a choice at all, merely an irrelevant event.
That feeling of freedom, that we can do something merely because we feel like it, a spur of the moment fancy perhaps, that feeling might be a mystery in the sense that we are not privy to the underlying operation of mind, but that should not licence us to imagine that there is some magic happening there. It is not magic, it is subliminal; it is no more magic than our ability to calculate that return of serve without even thinking about it.