I think I gave in easily when DD vetoed her grade skip to high school because I wasn't ready either. When she did go, 10 turning 11, I was also worried about the EF stuff but she thrived and became so much more organised and capable. It wasn't demanded of her before then! So they can surprise you. We didn't have the issue of buses and changing buses etc so there wasn't that pressure.
I do wonder though, if and when he gets to the middle school, whether you won't need to worry as much about extra activities and enrichment. The additional challenge with the EF side was almost enough to keep DD busy for a couple of months.
I am not sure your DH doesn't have a valid point that you are busy and do have a lot on your plate. The problem is there are just some things we do have to do no matter how tired and busy we are. And then we get tired and finding a way to make it all better becomes all the more elusive.
I hope you find sometime to breathe and then work out a plan for your DS. By the way, even though he doesn't have a diagnosed condition, some physical therapy can help improve his core strength and proprioception. I don't know how funding would work for you without a "named diagnosis". Some of the conditions related to hypermobility can be diagnoses of exclusion and not well understood by many people.
