Wow, thank you everyone, there have been so many responses that have really helped me pin certain things down.
@HMG107 you are right, I have concerns related to my own experiences with my DS' dad, my exDP. I appreciate you pointing out that I am showing here more concerns about the people around DS, including myself, more than I am about DS. And really, at the base of it, this isn't happening to me, really. It's happening to DS.
I do actually think that I have been able to be and move empathetically in response to DS. For example, since he was a tiny boy, I have seen his need to 'discharge' through repetitive movements, and was proactive in suggesting it to him when he felt overwhelmed. He now is able to see himself becoming overwhelmed, at which point he will say he needs some 'private time' and take himself off into his room (or somewhere private/ remote) to have a bit of a flap about. And I have always been able to see when he has run into trouble around having a compulsion to explore something in a tactile manner (for example by hitting or pushing it) when others have seen destruction or lack of care. I have been a good advocate for him and so far he hasn't actually experienced any negativity for his difficulties, although I have at times been in conflict with other caregivers when they have expected him to behave or believed he should be disciplined or punished for something which I can SEE is not about a lack of care or concern, or a desire for destruction or aggression. I therefore don't thiink I'm being completely unfair to exDP because in fact I really did love and appreciate his ND, and loved him for, not despite it. However, I did not find him able to reciprocate in that he could not love and appreciate who I am and he was constantly trying to get me to be and see things differently. I did not feel 'seen' by him although I really did feel that is exactly what I offered him. HOWEVER, as you point out this is all about me and exDP - it's not about DS and DS is not his dad.
@BogRollBOGOF
For "high functioning" people, the challenge is that people expect a "normal" standard from them and don't see the cost of masking. In families where there is a lot of high functioning autism, it can create an invisible culture of autistic behaviour which may be helpful, but may also create odd clashes and blind spots.
This rings sooooooo true. Indeed, when the referral and assessment process kicked off, it made me really look again at my own family, all my previous relationships, all my close friendships. We have made quite a lot of adjustments around DS without them feeling outrageous but to people outside they have looked outrageous. He still likes to have an adult to sleep with him. He needs a lot of touch to calm down at night. As I said above, he gets 'private time'. I have always done a lot of narrating transitions/ expectations/ preparation about new situations - because that's the kind of parenting he seemed to need AND the kind thing I feel I can do as a parent. The biggest adjustment we made is that we never sent him to school - he didn't look ready in terms of the kinds of behavioural expectations (still, calm, not being talked directly and personally through details of what is happening, for example). Our Consultant Paediatrician stated that with his cognitive profile, Home Ed is the best possible learning environment for him, so I feel really affirmed here. And it is a good example of how maybe just as a family we are already possibly ourselves ND and have automatically made adjustments which are beneficial but also speak to some blind spots.
So he has been scafolded a lot by me/ the family in ways that seemed straightforward to us but may look odd/ indulgent from the outside. As @TractorAndHeadphones observed there is a lot of ND in her close circle - when I think about it, it's pretty much the one thing all my close circle have in common. All of my exes are ND. My besties all have been And when I started talking to my family, it turned out my older brother was diagnosed a few years ago, and we had a lot of conversations about traits in the family around us. I had no idea before, or, I hadn't seen it before because it's just really normal for us. It might also be me as well in certain ways.