What you describe is a program that (in my not-professional opinion) would appeal to those one standard deviation from the norm, IQ 115 or so... the bright kids who find grade-level work satisfying and engaging. For the truly gifted child, it amounts to torture.
As for homework, I can say is that I'm adamantly opposed to any "gifted" program that punishes students by burying them under an avalanche of homework. The lesson the kids learn is, "Don't be smart," and I couldn't think of a worse lesson our schools could be teaching our children. Furthermore, gifted children do not need repetition. So unless they're doing research, projects, or the like, they should not be wasting their time.
I'm curious to know why you've ruled out moving up to middle school based on social issues, because it seems to me that if he hasn't found his place in a new elementary school yet, then changing to a new middle school wouldn't really change that.
