IEP trumps district/state standards in terms of one size testing fits all. Best example is state-wide standardized testing. There is a section on the IEP where it's noted if student will participate in standardized state-wide testing and what accommodations will be made if any. thank you gets the tests in small chunks with- extended time to do the tests, rather than the monster 3 straight days of testing that is done for reg. ed. students. There was one year where thank you was so completely unstable he was not required to participate in testing at all. It's not appropriate for Boo to participate in testing, so he participates in the "Illinois Alternative Assessment" - which in real terms boils down to he does no testing at all.
If IEP states less homework will be accepted, then less homework must be accepted. If you're running into specific issues, ie the math homework due to some "standard", I'd request another IEP mtg to address them. What accommodations does he need for the district standards?
Special Education is *not* the physical class that difficult child is in. Inclusive or self contained doesn't matter - it's what's in the IEP that defines "placement" and what the expectations are. "Placement" isn't a place, it's the Special Education programming, so their argument that because he's in an inclusive classroom he must follow district standards is just ridiculous, in my lay opinion.