He's a little young due to graduating high school in three years, so he wants to stay close to home. Plus, if he actually makes it all the way to National Merit Scholar, (he'll almost certainly be at least a finalist), UT-D has the best scholarship offer of pretty much any school. And STEM, so undergrad doesn't matter as much as other majors.
Definitely have him look at the McDermott Scholars program at UT-Dallas if he is in NM Finalist range. My career is college counseling, and the McDermott is one of the most outstanding scholarship programs in the country.
https://www.utdallas.edu/mcdermott/