Greetings fellow travelers [0]. [0] https://en.wikipedia.org/wiki/Twice_exceptional ---- In response to OP's link, my suggestion to primary schools would be to scrap the G/T programs, and instead focus on reducing class-sizes. You should also remove any students from classrooms whom routinely distract from others' learning. Give those timesinks a broom, instead.
There are only like 4 actual accelerated learning programs out of the hundreds in NYC's "G&T".