ED and EA

My son goes to a rural public school in North Florida. He is the only National Merit Semi Finalist in his school and the only one that will be applying to U of Chicago. Would this work in his favor for EA application? He is also applying to Florida State University and they will give him a complete scholarship if he gets National Merit Finalist so he doesn’t want to go ED and have to give up the possibility of a full ride in state. I think his application is competitive (34 ACT, 1470 SAT) 3.98 unweighted and 4.39 weighted.