The study I linked indicates that people who don't believe in free will act as if they don't, granted, they weren't warned of the dangers of believing they don'

The study I linked indicates that people who don't believe in free will act as if they don't, granted, they weren't warned of the dangers of believing they don't so there might be more to explore. But the question seems to me more about pragmatism vs realism than pragmatism vs. realism with 'some beliefs-as-if'. I find realism unsatisfying philosophically because we can see historical beliefs being so off the mark that we'd have to live in a pretty special time to have anything close to a realistic model of the universe, I think making good predictions is simply the best tool that we have. If that comes at the cost of having a single internally-consistent model of the universe, that's unfortunate, but at least I'm not attached to the wrong one. So if my belief in free will and my belief in Newtonian Mechanics are incompatible, that's not such a big deal to me as a pragmatist. In fact it's a useful feature of the metaphysics, since the places they come into conflict give an idea of where they're incomplete.