Thanks for the ideas, Portia! I suspect my question was a little too specialized!

I've been talking to the director of intervention services, and I think we have the starts of a plan. The principal relaxed on the high school credit approach for an 8th grader (whew!), and the director of intervention services has identified testing that will get to DS's writing needs in a more nuanced way than TOWL can. A particularly talented 10th grade, honors English teacher will then construct the assignments, provide a rubric for the targets, and the tutor will work through the assignments + Writing Matters to support it all.

There are 14 school days until this has to start, though, and I'm anxious about not having things more firmly in place! None of the testing or specific plans seem to have actually happened yet.