2 of the 3 different things need to be submitted, so if the achievement scores don't meet the qualifying, don't send them - send the portfolio instead.
Put in conversations you have that show in-depth knowledge, record them discussing something, written pieces of work that are clearly 2 or more years above their age peers. Pictures and written explanations of projects they have done.
DYS is looking for academic stuff, so they are not interested in sports ability or musical ability, keep it to things that could be considered "core classes" topics in school.

We've used the educational consultants for DDnow12, when we were radically accelerating her and the school wanted to know more information about intensities and how to deal with a young kid in a middle school. We had the guidance counselor be the school's point person, and then whenever there were questions form teachers or admin, this person could (and did) call the family consultant and talk with her. It was great because then it wasn't just DH and I saying she needed this that and the other thing, but rather people the school felt had more legitimacy because of their position. We were able to get things sorted out much faster with the consultant than we would have been able to do on our own.