To think if we can't get help, who can?

I'm absolutely certain a year at home would be awful for everyone.
DH would get no respite and his mental health is on a knife edge. He's had panic attacks before and DS finds them hilarious and an excellent outcome to his behaviour.
This would lead to escalation and I'm not at all sure DH wouldn't end up hospitalised.

DS would have no contact at all with other children or adults other than us.

DD would also get no time without DS.

And I'd spend a lot more time trying to WFH with DS needing attention.

As I say, he enjoys school. School doesn't enjoy him!

Thanks @Jellycatspyjamas - I am a scientist by training and look for meta-analyses, RCTs, and systematic reviews. You are right that most of the "this is good for adopted children" interventions have little evidence and that is partly why we steer clear of them (also, we don't think it is going to do DS much good if we are trying to get him to participate in something with an unknown therapist when he's basically not going to engage, though school are welcome to try if they think they can - unfortunately they tend to say "he won't engage with therapy" full stop and then don't try with things that we think he COULD do e.g. OT practice, which he quite likes).

Behavioural type interventions work well for ADHD
https://www.sciencedirect.com/science/article/pii/S0890856714004080

(note as I've said before this isn't ABA).

Here's an RCT on CBT for adults with ADHD (looking forward to him being an adult!)
https://link.springer.com/article/10.1007/s00406-016-0735-0

This is the anxiety programme we are using (this is for children with just anxiety, but the programme has also been successful in ARFID, and the clinic reports they use it with ASD and ADHD, though I don't think they have RCTs out yet. It looks like some children in this study had ADHD but they excluded ASD for this particular trial).

https://www.sciencedirect.com/science/article/pii/S089085671930173X

This is an interesting meta-analysis on family accommodation (making changes to make the child less anxious) increasing anxiety. It does point out most of the studies are cross-sectional (but some are not, and if you remove accommodation, you decrease anxiety).

https://link.springer.com/article/10.1007/s10578-020-00987-6

This is a systematic review of Theraplay for children: our DS is now older than this, but none of the studies included children with significant behaviour issues anyway, they were mainly social anxiety/internalising problems:

https://acamh.onlinelibrary.wiley.com/doi/full/10.1111/camh.12416

This shows that enhancing maternal sensitivity improves attachment in children with diagnosed difficulties with attachment (but DS doesn't meet the criteria for this).

https://europepmc.org/article/nbk/nbk305116

I know some people swear by DDP but there are no trials/systematic reviews on that that I can find.

Anyway lunchbreak over, must get on with some work as we have the Post Adoption Support person coming later!

We are, but with the alternative of him staying there until we get another place, or being offrolled and left at home, we'd choose him staying there. They were threatening to remove him immediately assuming it would make the LEA take action - we know it wouldn't.
They do know the LEA are crap, and there are few schools available (which isn't entirely the LEA's fault) but it will help nobody if he is at home for a year.

(We did tell them they were incorrect that the LEA would "have to find" another school, which seemed to shock them. And we keep telling them how much he seems to like school -he told us yesterday he'd be taking in his crafts to show Sir).

I don't know what we can do to avoid the school saying they can't meet need.
They just see his behaviour as so severe. We have made loads of suggestions and we agree to whatever they want to do in school eg art therapy. It isn't going to make him worse, we just have no confidence it will help.

We can't tell DS "don't kick off so you get to go to the calm down room and do your colouring". Well I mean we can but it would change nothing.
We could lie about him reading and doing other work at home but he'd tell them anyway.

Sorry I should also say, because this is all gloom and doom - DS is slowly recovering from his epilepsy admission but the doctors were unsure how long this would take! He's still struggling with instructions but has been getting back to his creative self, he now has a craft book he seems to want to work through over the summer, DH, DD and he went to the beach yesterday to get some shells to make a turtle.

We went to an outdoor play on Sat and as usual with the first suggestion of anything he said I'M NOT GOING but we just waited for him in the car when we were ready to go and off we went.

He's got 1:1 swimming lessons this week so I'm waiting to see how those went.

(I can't remember if I mentioned that school said "well we can just say we can't meet need and the LEA will HAVE to find him a school". No, we said, if you do that he'll be at home with no education and his anxiety getting worse and worse and never going out, because the LEA have left lots of children in this situation when they stopped attending or the school said they can't meet need. I think the. school are living in cloud cuckoo land).

I don't think it either will or should be necessary. In fact it's bananas when you look at his capabilities now to even think such a thing. But I also suspect that, as with all these things, it's only available if you are well behaved. If not, then they will just do as school has done, wash their hands and send him home.

It would be ridiculous for him to be in supported accommodation because we were afraid to teach him how to cook and do his washing, so we just did it all for him, when he's actually already partially capable of doing these.

Likewise it would be ridiculous to say "don't bother advancing his academic education because he doesn't like it" when he's actually very keen on learning when it's presented in the right way.

To us, everyone else seems to have given up on him having a full life, but we refuse to do so.
And it also seems like everyone else wants to protect him entirely from everything that makes him anxious because they are completely unaware of the fact that lack of exposure to things that might make you anxious, just makes you more anxious.

We have spoken about residential care but unless it's a very good school (please don't tell me they are out there, I'm sure they are but they won't take him) we are fairly certain he would just come back to us bigger and more aggressive aged 18 with no more education and no better self regulation. Given the news around NW SEMH schools which are full of abusers (Wirral Life and Wings Cumbria) he would probably come back traumatised and abused.

In case it's not clear @cansu tolerable is exactly what we are aiming for.
But "tolerable with no life skills and no qualifications and living in his room gaming 24/7" is not going to get us a child who can be independent at 18. "tolerable with some skills and some qualifications" is what he needs.

Because of his profile, if he isn't independent as an adult he's going to be in prison. Not in residential care. It might be different if you have a child with a learning disability or with autism of the kind that prevents independent living but just as they don't make schools for children with behaviour problems but no learning disability, so don't make adult residential care for them either. Except, as I say, prison.

@Attention we try very hard not to talk about school's failings in his hearing!

We said nothing to him in this instance and told school what he'd said and that in our opinion their constant (daily) sending him to the isolation/support/calm down area was now a reward for him. They just said they tell him to do his academic work in the support area (but we know he has no incentive to do so) and they can't do anything else (we made lots of suggestions based on what works at home but they "can't do" any of them.

For example, if you keep talking to him after you've told him to do something, he finds it very hard, we tell him and then stay quiet but his home-school book is full of "he was reminded several times to do X"; we find it is best for him to calm himself down with nobody else with him and definitely nobody talking to him but they say "oh he just follows his 1:1 when he's upset" - at home we then would go to another room or guide him to run around outside (they have masses of outside at school, way more than us, and his classroom has a nice foyer where he can be safe and even throw the beanbag chair if he needs to)

I don't think they believe us or, indeed, understand behaviour analysis (note I don't mean ABA, just working out causes and consequences, so ABCs as others have mentioned).

Here is an article on therapies in ADHD. Note that behavioural therapy for children (which is pretty much what we do, and we're getting much better at not giving negative attention for negative behaviour) and talk therapy for adults are noted to have research behind them but the other therapies for children are only "nice idea" and recommended by the therapists (well DOH).
We do actually use an ADHD coach (ADHD Dude who takes a very behavioural approach and it's working.

www.additudemag.com/add-adhd-therapy/

Given that about 5 other agencies have tried talking therapies with him and he mainly hides, you'll forgive me for being sceptical. Same with eg art therapy at school. He spent 2 weeks hiding, 4 weeks colouring and it made no difference to his behaviour (which was why they wanted to do it).

And yes, being independent and having the resilience to do things he doesn't particularly want to (whether that's homework, helping around the house, or being in groups with other children/being away from us) IS progress. Becoming less anxious about doing new things IS progress. I'm not sure what you think progress is?

Given he's literally come home from school and said "I will kick off so I can go to the calm down room and do my colouring" I think they might need a different approach, don't you?

More updates:
DS has been pretty ill (epilepsy, hospital, I was away with work but by the time I looked into changing my flight he was home again, my mum who can be really controlling was an angel and looked after DD but DH was glad to see her go). He's still quite groggy and clearly having his brain shut down almost entirely for half a week followed by the rescue meds (IV) not leaving his system for half a week has left him with problems following instructions, remembering things he definitely knows, and a few "stuck record" situations.

So we are obviously taking it gently and this week working on a few easy things like trying on t-shirts that may be too small and helping to clear the table before tea.

He was supposed to have a last trial session with a youth worker but surprise surprise didn't engage (we said he wouldn't) but honestly, since talking therapy is not recommended for children with ADHD we are not sure why they bothered.

School however have been a PITA. Had our ECHP review and they basically said they'll lie to get rid of him. We have told them ALL the things that are helping us at home and pointed out a few things he has said to us which suggest they might not be getting things right and they basically have refused to try anything different. Given it's a specialist school and he has a 1:1 and these are all things that work at home I'm not quite sure what else we are supposed to do.

One of the regional SEMH schools has been shut down (not the Wirral one, another one) due to abuse. It's a very scary time.

On a positive note we have 1:1 swimming for him which he really enjoyed at half term so we're hoping his brain kicks into gear for that, it's next week.