Welcome!
From what you have described, it may be that a little more unstructured time would allow both your children some breathing room for imagination. Honestly, they don't have to have -extreme- imaginative OE to benefit from unstructured time. Routine is important to individuals with executive function weaknesses, but so is flexibility. I'd first want to see how they present while engaged in their extracurriculars, though, as those are creative activities, that might be the only times during the week where their imaginative cravings actually are met. Do you see the same EF struggles when it comes to dance/music lessons and rehearsals?
In class, the lack of focus may have multiple possible origins. They may simply be understimulated, by a mismatch between their personal instructional needs (zone of proximal development) and the low level of instruction provided. If the homework doesn't appear meaningful to them (due to the low instructional level, or being perceived as busy work), it may be insufficiently engaging for them to remember to do it or hand it in. At home, it may help to create visual checklists for routine activities, posted in the places they are most likely to see and do them. And FWIW, requiring multiple prompts for the daily activities you described is not out of the range of typical for this age.
There is certainly value in making mundane activities into a game or a challenge. I know GT adults who think fondly back to making dishwashing into a game (maximizing efficiency by sorting into compact data packets! optimizing circulation of water around utensils by determining the best mixture of flatware of different shapes!).
Some practical skills resources on EF:
"Smart but Scattered" - Peg Dawson
https://www.amazon.com/Smart-but-Scattered-Revolutionary-Executive/dp/1593854455HOPS: "Improving Children's Homework, Organization, and Planning Skills" - Joshua Langberg
https://www.nasponline.org/books-and-products/products/books/titles/hops-for-parents
