Questions,

My DD7 is in a similar situation. She doesn't want to grade skip right now. I'm not pushing it because the gifted program starting in third grade amounts to a 1 year grade skip and the magnet amounts to a 2 year grade skip, from what I'm told. It's been challenging keeping her engaged. Sometimes the teacher has a little flexibility to give the child different work in the classroom. It's worth a try. I know that my DD can put up with some repetitive work, but not all repetitive. She does better even if she can have a little time each day to be challenged. FWIW I am investigating home schooling. I'm not ready to commit to it right now, but I am preparing for it and collecting resources if I need to in the future.
I understand what some are telling you, that your child doesn't get to decide that he doesn't like school. DH and I do all of our advocating unbeknownst to DD's. They don't need to be involved, it's not their responsibility to fix the problem. I do believe that it is okay for DD to understand there are times at school things won't go her way. You have to go along to get along.......However, she should not be bored, understimulated, not learning anything ALL the time. The school setting is what it is and I've accepted that neither daughter will get all thay they need educationally, that's why I "afterschool". However, it's a balancing act and if the child is experiencing stress at being continuously underchallenged, I think you have to do something about that. There are no simple solutions or easy answers. If school is not doing anything extra to make sure my child has a good education, shame on them. If this is happening and I know about it and am not doing anything about it, shame on me.
I have tried to find resources to support their interests. We "play" at math and LA activities at home. I take them to area museums as often as possible and look for free classes there. They each get private music lessons. I'm trying out a home school science group for DD5, it's in the afternoon and she is out of K by then. And when I have noticed the are having issues because of understimulation at school, I start with the their individual teachers and work my way up. I've been in the school alot this year and so far have felt like the school is doing a fair job working with us. I will say I've noticed that the school likes to come up with their own ideas about how to solve the problem. They seem to be okay to work with because I haven't told them what to do, only told them what the problem is. I can't tell you how any of this has worked out because we are still in the middle of it all, kind or like you.
A plan is not a good plan if it's inflexible. Any good plan can be changed at any time.
That's how I feel about this journey I'm taking with my girls. We're all stumbling throught this process the best we can and if Plan A doesn't work out, have Plans B, C, D, E, F, G etc. ready and waiting to go.
And Krison, I hear what you are saying, some GT kids can tolerate boredom, get along, still get good grades. Sadly, I am an example of the worst case scenario of what can happen when a gifted child in not accomodated in school.

Well, good luck questions, wish I had better thoughts for you,

Incog