Thank you, ladies, for your comments so far. Today was a much better day for him in his attitude and his willingness to do what was assigned. Telling him he'd only have to write one subject (I left a note for him on his alarm clock) did change his attitude toward school. Unfortunately he still had 3 subjects unfinished (9yo had 1) besides painting for poetry left for the afternoon. He had at least a 1/2 hour when I gave him specific work to do and none was done. (Though I admit it was a distracting morning with DH coming through, special mail delivered and smaller siblings getting hurt.) However, there were no melt-downs, yelling or subjects left that I have to help him with! Yay!
In fact, one subject that I expected to be met with balking and complaints went fairly well today (even if it does take longer, scribing for both boys). WWTB had the first actual written assignment in Unit 1 Day 8 and this is my 12yo's descriptive paragraph which he dictated to me (we used a LEGO custom-painted mini-figure that he painted):
There once was a strange elfin warrior from the land of Ablog, who isn't the type of warrior you'd make him out to be by his looks. He was a bit skinny but not so skinny that he didn't have the looks of a warrior. In place of a helmet he wore a large hat that dropped off to one side and covered what would have been the top half of his right ear which he had lost as a young boy and would tell no one of how it had happened. He wielded a great, gleaming, sword. He also carried a large shield that, despite its looks, was quite light and wore a belt that was too big for his waist so the end hung down to his knees. Despite his mature facial expression he usually managed to get into trouble and was disliked by most of the knights of the land because, for some reason, the princess favoured him above the others.
Writing (or even typing) that himself he would have given no where near that kind of paragraph. (Like maybe 3 short sentences.) I realize there's a bit more narrative in there than an actual descriptive paragraph maybe should have but that's probably my guidance more than his discretion (I didn't look at the overall curriculum with "description of a character" to come later

)
Lynn, I had just thought of typing dictation this morning - we'll try that tomorrow (we didn't do that today).
Would you consider passing on my email address to your friend and asking her to contact me? (If so, I'll message you privately.) I looked at some Executive Functioning checklists and he has every single one of this one (except for walking & talking on the phone - he's not tried that, lol):
Is this your child?
Keeps a messy room and a disorganized desk
Has difficulty following sequential instructions
Has trouble sitting still when others don’t?
Needs to be nagged repeatedly to get ready to catch the bus?
Fails to complete assignments unless you’re standing over him?
Forgets to turn in homework even when it’s completed?
Loses things regularly, from jackets to permission slips?
Has a meltdown when it’s time to clean her room?
Has difficulty planning and managing time?
Fails to control his impulse to lash out when frustrated?
Forgets to pay attention to where she’s going when talking on her phone?
Engages in risk-taking or thrill-seeking behaviors
This leaves me even more overwhelmed. More to deal with, teach and modify. It's not like any of this is new, but having a term to validate that there's actually a bunch of symptoms here that fit together into something "diagnosable" is both reassuring and overwhelming at the same time.
Carrie, I really appreciate your comments and will certainly consider whether to move down or not. I really don't want to, though. One reason is that I will already have to change enough to make things High School worthy for him (LA, Science, etc. not to mention Canadian history, which I'll leave for another year

). Another is that he is definitely ready for the other content of CTC (topics, reading level, etc.). He is loving the Extensions (I allow him to type those written narrations and he's started with just one paragraph with the ideal in mind for him to be giving 2 by Christmas or so and definitely 3-4 by the end of the year). I think, from what I've seen with my DD doing Preparing that he would find it too simplistic (although he wouldn't mind the drawing that she is balking at, lol). (He's already done AO Year 5 - to give you some background of the lit he's already dealt with.)
You said, "With your son being new to much writing though, it is possible that he just hasn't had much practice in this area." While this is true to some extent, looking up dysgraphia last night he has all the signs (capitals in the middle of words; incorrect grip - too tight, which we've worked on before; poor spacing; inconsistent spelling; fatigue when writing, etc.). I think this means that he would have trouble with the writing even in Bigger! I'm thinking (though I can still probably be persuaded otherwise) that allowing modifications (typing, scribing, voice to text) and teaching editing skills while keeping the literature, cognitive and content levels at closer to age-appropriate levels would probably be best. (We're also trying to incorporate some of Dianne Craft's Brain Training outside of school hours to help with fluency in writing this year.)
As for the executive functioning, I guess for now I'll continue to make him checklists (he's left-brained so visual spacial, ie having his checklist set up in the same visual format as the guide, seems to be best for now - we tried a linear checklist similar to those we used last year in Unit 1 and that failed) and teach him processes for subject transitions (hopefully gently reminding him to go back to his checklist and the guide for direction instead of to me) while I continue to research if there's anything else that will help him (and consider testing so I know I'm not a vicarious hypochondriac!

).
So far we're on track to finish a 4-day Unit in 5 (or possibly 5 1/4) school days this week, which is slowly an improvement from last week's 2 days in 3. I think that we can get to full speed with accommodations, even if that ends up meaning 1 unit per 5-day week for us, since I'm spread so thin.
And Jennymommy, I like that idea. It sounds like the timer idea might take
more monitoring unless they want to use it (voluntarily set their work aside for later when the timer goes off). We do try to keep to those general time guidelines during our day but it mostly only works for when I'm with them. My self-paced learners would work well with it while my oldest would find the pressure of a timer defeating (I'm NEVER done when it goes off). I may try to implement a version of it though. . . thanks for the food for thought!
Thanks for your input, too, Stacey. It's good to know I'm not the only one with these things to ponder.
Does all this make sense? This is the first day with a glimmer of hope in a few weeks (so much for a "honeymoon period"!), so thanks for helping me talk it all through.
Overwhelmed but counting my blessings, (HOD, Carrie, this discussion board, supportive parents, small victories. . . )