I agree Lulu, 1 hour homework for year 3 is a bit much no matter how gifted the child. Homework at this age is not supposed to be difficult. It is revision so it should be able to be completed quite easily (apart from research topics). Homework at this age covers the work they have been doing in class.

I wouldn't be concerned about the homework at all. Writing a personal homework sheet does take time for the teacher and you can extend him yourself at home. I would be more concerned about the classroom. That is where you don't want him to get bored. Is the teacher giving him extension work when he finishes so quickly or does he just sit there? I would be focusing more on the extension work rather than the personalised program. Extension work can start right away. As Lulu said a personalised program takes a lot of preparation and money.

Extend him yourself at home but don't push it. Even gifted and talented children need to be kids. That's great you found some science kits. There are some really good ones that challenge the mind of young ones and old ones too.