Right, sorry to be abrupt there. Dc calls and all that.
As I was saying, ds1 (our second born) has always been a troublesome, agitated child. Right from teeny tiny. As he's got older he's moved on from screaming and tantrumming to shouting and lasting out, violently, and myself and his siblings. Dh not so much but that's usually because I'm sahm so bear the brunt.
Your plan to give your son some space from your family, but still within the wider family, is clearly one you have not reached lightly. But it does sound a good one.
You will have some space to look after yourself as well as your son's siblings. He will have plenty of time where he is the youngest child and the older ones will look after him.
But you are still sharing family life together by making it a part time in the week arrangement. It sounds like he will be elsewhere for the high pressure parts of the week - going to school, maintaining a routine which isn't always possible with little ones. And then coming together at weekends when you'll have more time and less stressed upon you as an individual.
Ds1 used to stay with his paternal grandparents one night a week every week until he started school. Unfortunately fil's ill health has also had a knock on effect to sleepovers in the holidays. But I so looked forward to that one night where I didn't have to worry about ds1 and he had 2:1 attention so was safe.
We have no diagnosis. Save he's 'a little angel at school'. But we are pursuing all avenues open to us.
You need to think what would best suit you as a family and which keeps the lines of communication open between you and ds. Having him live with family is surely the best option. I think you are doing your best in very difficult circumstances and I think you should trust in your instincts more. You know your son and family set up to know whether he will ever feel like he's been shipped out. But I truly hope your solution works for you and you all come together as a happy family together in the future.