I think that people haven't responded yet because you used the word "blog" which is confusing, this is just a website, I believe.
I am not an expert on things gifted or on things DYS. However, I do have a daughter who is DYS. I think that if you can read all of the articles here and at Hoagies and can advocate using the tests that you already have, then you have succeeded in what it seems like you most need. You can also ask for end of year benchmark tests to get additional scores.
It is hard to tell you what you need and if it will be worth it for you, given the time and expense. I would do the IQ and send in the achievement in the form of supplemental materials, if you decide to do testing.
My daughter has gotten a lot out of DYS and we are really grateful to them, but it is hard to say that it would be right for you.
