I think I'm lousy at the advocacy, so I'll leave specific advice to wiser heads. (That's a big factor in our decision to homeschool, frankly. I couldn't imagine how I'd survive the eternal dance of trying to push hard enough to get change, but not pushing so hard as to alienate everyone in the school. My autism spectrum score seems relevant here...)
Hopefully your experience with mediation will help you here. You know how to work to consensus.
I can tell you what I've read here that has seemed to work for people: do pretty much what you're doing. Pose it as a problem ala "DS is miserable and resisting school in a way that is very distressing and not normal for him. I'm concerned. Could you help me with this?" (Only written better than that, of course. In meetings, it's supposed to be not a bad thing to cry if you are at that point, whereas normally you'd want to stifle tears at all costs. Don't fake them, but don't hide them either.) Then let the school suggest solutions and pick the ones that work for you.
Do not use the word "bored" or even hint at it. People worry a lot more about unhappy kids than they do about bored ones.
This will be a long process. If you feel your DS can't take it, then I think you may have to seriously consider other options like a change of schools or homeschooling. (That's how we began our year of "emergency homeschooling"--same exact scenario as yours!--highly upset child, no sign of progress, no idea how he could last the year that way, etc.) Schools move on something akin to geologic time for things like this. If the psych is slowing you down, too, I suspect you are not going to see much help this year, just given the timeline. It's why I worry about following the psych's advice and waiting a month until you have her report (though I absolutely recognize that she presumably has expertise with the schools that I do NOT have). But every day you wait is another day closer to the end of the year with no changes made.
Kids are resiliant, and one bad year isn't likely to do scads of permanent damage. That's the bright side. But damage *is* being done when a child is that upset about something that is what he does for most of his day. It's just not okay IMHO.
