Calvinists and OSAS believers must believe they are literally "frozen" and don't really move. Here's why
According to many Calvinists, there is no such thing as any incompatabilist free choice at all. In fact to some like Paul Helm God's own foreknowledge is incompatible with any notion of incompatabilistic freedom as he argues in "Eternal God: A Study of God without Time". In this monumental attempt to argue for God beyond time which is laudable, Helm makes the case that God timelessly creates the universe and it makes no sense to say "when" this takes place. Given this, as Helm also posits that "then we can say, by extension, that God has produced every event that the universe contains"(pg.69). Indeed Helm's elaboration of this is wide enough to accommodate an indeterminist view(pg.70) but given his rejection of this, it entails that God must also determine the actions of these agents by actually producing these events as he wants them to unfold. When addressing the argument that an agent's free act to do A is based on God's will that the agent freely does A need not compromise indeterminist freedom, he accepts this logic but sees it as compromising it(pg.165). Hence it would certainly be the case that for one to A, God must also will or ordain that one As.
In "Calvin at the Centre", Helm uses a similar way to describe Calvin and Stoic compatabilism where he states against the argument that if determinism is true, what we do doesn't matter:
>while it was eternally ordained by God (let us suppose) that Joe climbs the ladder, God’s decree that he does so is a necessary condition of the truth of ‘Joe climbed the ladder’. But it is not by itself sufficient, because the decree has also to take effect in time. In ordaining that Joe climb the ladder God must also ordain that there is an available ladder, that Joe was not too frightened to climb it, that he had an objective for which ladder-climbing is necessary, the desire to climb, and so forth. And for this sort of scenario to be a cure for Joe’s idleness then he must want to climb the ladder, knowing or believing that it is (probably) connected with something further that he wants to achieve. Such factors have to be ordained in the correct causal and teleological order and to ‘fall out’ thus.(pg.243)
Here, for Joe to actually climb the ladder, it must be because God from his eternity willed that Joe climbs the ladder which must take effect temporally and involve God willing other conditions such as having an actual ladder for Joe to climb and his dispositions to be able to will to climb it. Joe's movements is ultimately because another agent from eternity willed it to be so and it is necessitated as such. Of course these to Calvin and the Stoics does not excuse them of idleness as humans don't have access or knowledge of the future and that "effort is causally contributory to an envisaged end"(pg.244). Hence we must also act as if the future is open(pg.245). Regardless, all actions are still necessitated by God's ordination(pg.247) and decree and hence the future is truly set in stone.
So with this determinism in mind in Calvin and the prominent Calvinist theologian Paul Helm who takes the compatabilist view, how does all these relate to my statement that Calvinists and OSAS believers must believe they are "frozen". This is simple, many reviews of Helm's "Eternal God" have noted that Helm is espousing what is known as the B-Series theory of time.
For instance:
https://www.amazon.com/Eternal-God-Study-without-Time/dp/0199590389
And in WLC's review: https://www.reasonablefaith.org/writings/scholarly-writings/divine-eternity/a-review-of-paul-helms-eternal-god/
And Helm's own espousal of this theory of time: https://paulhelmsdeep.blogspot.com/2008/01/eternalism-contra-craig.html