My experience is not with a private gifted school, so results may vary, but my DD has spent over two years now dealing with two different schools who talk a good game about differentiation, but putting it into practice with any kind of consistency seems beyond them. So my advice would be to put the screws to the school to prove their words before entertaining the idea of redshirting. If you can, sit in on a class and see if there's anything resembling differentiation actually happening, because if this is truly a school for the gifted, your son should not be the only one there dealing with this.
