Hypothetically, science proves free will isn't real

[Neo-Scholastic]

…brains which evolved as a means to survival.

In order to find and prepare food, it's necessary that our internal model of the world in some way correspond to what's out there, or else we wouldn't survive. There's reason to suspect that our perceptions are veridical. What makes you think evolution didn't design us to be capable of reason?

Your answer seems circular: humans survive because they can reason and we know they can reason because they survive. This type of answer reflects a general problem with tracing everything back to evolution. The fittest survive and we know they are the fittest because they survived.
It would seem that the mental abilities of humans serve well-enough the way we live. So do those of wasps, frogs, and horses. The question is whether reasoning is an advanced form of instinct or a different kind of thinking altogether. I believe it is because 1) instinctual reactions seem directly related to the physical environment of organisms, including Man, whereas the referents of reasoning are abstracted concepts and 2) concepts have positive ontological status.
This is not to say that the realist position is without problems (which I feel can be resolved). Rather, that as a theory it explains more of the relevant phenomena than competing positions that have their own problems (which I find intractable).

Mental events that yield reproductive advantages to the species do not necessarily correspond to things as they are.

And they don't necessarily not correspond to the way things are. The proof is in the pudding. In some ways the mind and perception can accurately model reality, in other ways, our biases, it does not.

Since the pragmatic approach to everyday living and even natural science works, I also say go with it - methogologically. At the same time, you’re avoiding the question of whether it is possible for reason to overcome natural biases when dealing with ultimate issues. If it cannot then rationality has limits that prevent justification of everyday and scientific observations and there’s no way to know how far down that rabbit hole goes or accounting for the arbitrary point at which you stop trusting reason.

Ultimately our behavior is non-rational; it does not conform to logic. Reason is but a small part of the self. You seem to think this 'not conforming to things-as-they-are' is some sort of horrific bugbear.

Most days it’s not. Most people go along to get along most of the time. And of course we don’t go through life like Vulcans logically calculating our every move. That’s irrelevant. This is philosophy and since its inception philosophy has been all about trying to figure out how things really are on the deepest possible level. Some say that science has replaced philosophy and for some things it has, but it hasn’t entirely displaced it; but rather, science still rests on the foundation of philosophy. Again, reason may be a small part of self, but that says nothing about whether it can overcome the self’s limitations.

… if we play on the other side of the fence, postulating that a perfectly rational superbeing imbued us and the universe with intelligibility doesn't get around the skeptical objections either. Ultimately there's no justifiable reason for suspecting that an ultimate being isn't deceiving us about things-as-they-are. It's no less an arbitrary assumption than is supposing that reason which comports with things-as-they-are has some sort of evolutionary value.

The existence of God is not my starting premise. My starting points are 1) the universe is intelligible and 2) human reason is effective. I freely acknowledge that those are existential commitments. I think knowledge of God’s existence follows from those commitments and reliable observations about reality. Skeptics make different existential commitments. Those commitments undermine the arguments for the existence of God. Those same commitments, as they relate to philosophical questions, come at great cost. They lead to paradoxes that undermine the veracity of reason or make ultimate reality absurd. That is the essence of my reply to the OP. Sure, determinism undermines many religious doctrines but in so doing it throws the baby out with the bathwater.