Yes, but nobody forces you to use all 60 or so AP/DE credits. Yes, CC may not be challenging, but that means he may have time for other stuff and if he stays disciplined, transferring in would be a breeze.
The key point is that you would only have to pay for 2 years of college.
But first you should look to see if any of the CC’s in the U of I Engineering Pathways program are near you.
Or he probably could forgo the Engineering Pathways admissions guarantee and transfer in after a single year of CC.
Otherwise, UA-Huntsville and UT-Dallas are known for STEM. UT-Dallas has some big (full-tuition/ride) scholarship programs that he would be competitive for.