polarbear - funny you should be the first to respond, because you're at the top of my "follow up about DS" list. I have saved several of your posts where you mention traits you've found associated with expressive language disorder. They are VERY familiar. Though I never would have thought to connect the motley crew of odd habits and symptoms you've listed at various times - from lack of imaginary play, extreme literalness and inability to express feelings, to shyness, lack of eye contact, and phone phobia... Together with inability to write, in our house we just called it... being an engineer.

DS is clearly a product of his gene pool, both sides.
All writing is very difficult for DS, including simple and fact-based work, so it's difficult to say if open-ended tasks are harder. What little he writes, however, is considered excellent by his teachers (both content and grammar-wise). Though picking up on aeh's comment in Lepa's post today about WPPSI scores, I may be projecting but there might be something to DS having a harder time expressing more nuanced inferences (such as moving beyond his one-line essay question response to "why do you think that? Justify your answer/ provide evidence for your statement").
I did actually tried to do some preliminary research on expressive language disorders based on one of your earlier posts, but everything I've googled seems to focus on cases where language skills are obviously limited - nothing that remotely connects with a vocabulary at 99.9th percentile! Do you have any links or resources you've found that look at what expressive language disorder might look like in a 2E situation? While your personal descriptions are very DS, what I can find on the web bears no resemblance at all.
bluemagic - your post came through while I was reviewing old posts by polarbear, and oh yes, we have seen anxiety in the classroom when writing becomes impossible. I hope now you can see your DS finding some mental peace along with easier academics. Do please share what interventions/ accommodations make the most difference for him.
Your post brings me right back to kathleen'smum. How is a written expressive disorder different from stealth dyslexia? What you you see differently in everyday life, and what would appear differently during assessment? And then back round to polarbear, how do you distinguish between executive function vs. expressive disorders? A lot of DS looks like AHHD-I… As both kathleen'smum and bluemagic have noted, it's really hard to find the right remediation and accommodations if you don't know what you're dealing with.
I really appreciate the different perspectives. Your experiences are invaluable for helping us try to figure out if there's something we can do about this problem that supposedly isn't a problem, even though it causes everyone involved so much problem!