It doesn't answer the bigger overarching questions, but with strong creativity and visualization I'd try mental walking paths techniques for task/sequence memory. Presuming he is good at navigating? If he can vividly walk through your house in his mind, he can build a visual map of specific locations in that walking sequence.
Such as: I walk past the table in the foyer, to the sofa in the living room, to the dining room table, to the counter in the kitchen, to my desk in my bedroom. Or such. Then if he needs to remember a sequence of activities, he visualizes each item into each location like:
1) Get Dressed
2) Eat Cereal
3) Drink Milk
4) Brush Teeth
5) Comb Hair
Becomes a:
1) A pile of clothes on the foyer table
2) A box of favorite cereal sitting down on the sofa (with a remote control in its hand?)
3) A cow standing on the dining room table
4) A wind-up set of teeth bouncing around the kitchen counter
5) A giant magenta wig on his desk
I'm a fan of leveraging strengths.
