FWIW, he is going to be VERY OBVIOUS once he is in the classroom. Like my other child, he does not hide his light under a bushel. However, bureaucracy being what it is, who knows if they'll want to/be able to switch him if they put him in the "wrong" class?
Also, they will test him themselves for free in K (they test early at this school).
Well, that's the question. Our school system tests in kindergarten, and somehow they still decided not to test my Sylvia-Plath-quoting, medical-dictionary-reading five year old or her fascinated-with-negative-integers twin brother. The kindergarten teacher and I were...astonished. But there they were. I was, two years later, fairly amused when the children who had been labeled "not exactly gifted material" (in the most disdainful of tones) beat the cutoff for the program handily.