We have a DYS but I don't know a lot about the admissions criteria. What I will say is that whether you apply to Davidson or not, with your son's talents I think it is time to find other people to bring into his academic life. That could be in the form of mentors, teachers, etc. Maybe a friend has a dad or a neighbor who is a retired engineer or scientist. Perhaps there is community organization for adults interested in birdwatching, computer programming, astronomy or some other interest your son might have and they would welcome a younger talented person. I would start looking around and seeing who you can find.
I'm vary curious about what you are saying about your state law. Would you care to share what state? We have a child in early college and know many from other states and I've never encountered a law such as this and it makes me wonder about the source of the information. I will say as a general rule, don't listen to the first answer you hear if it is no. Often that answer can shift when they see those sorts of ACT scores.
Also, I would encourage you to start at the college departmental level. Approach the math department and ask for advice. Perhaps they know of a "math circle" for high school students in your area or perhaps they could connect him with a grad student who could tutor him or they might offer to let him audit a course. I agree with LilMick - it is fortunate your son's strongest talents are in math because it is a world that really understands younger talented students.
