I think if it was novelty I would have done it years ago. I am deciding whether to put my oldest in private or public school for middle school next year.
You could ask the private school(s) if they honor the district's identification of gifted/talented. You can ask for their written acceleration policy. You might need further testing - might not. I think you'll find more answer in each school's polices and in your state's educational laws than you'll find in your children's IQ scores.
IQ testing may become of value if you find that a school's gifted/talented program is not enough. GT programs are usually designed for the "high achieving" student, and an extremely or profoundly gifted child is still going to find the pace is too slow and the material too easy. This is where determining "how gifted" a child is can help in advocating for further academic challenge.
