As for explaining his work it is hit or miss for DS often depending on mood. I do worry that this could end up being held against him.
This is why I suggested having you ask him to explain his work to you at home, and you scribe his answers. You'll have a chance to get examples over a window of time, when he's actually feeling like answering - and you can use those as examples of his level of comprehension and understanding at your meeting.
We've had to advocate quite a bit from a slightly different perspective (2e), and we often found ourselves at meetings where the school staff would use one random example of something ds did in class as "proof" of his ability/level of work/etc.... those examples were all carefully selected to prop up the school's position re where to place ds. I found the same strategy worked very well for countering the school's argument, by having my own set of examples of ds' level of work
polarbear
