However, the school called me yesterday and made a massive issue about his behaviour at a school trip - when he was just being a bit misbehaved.
They should make a massive issue. It's a safeguarding issue. He was off the premises. They can't have that as it means he's a danger to himself and others.
Being a bit misbehaves misses the point that they need to have well behaved children for a school trip. They don't have the capacity to deal with a child who is missing behaving off the limits and keep an eye on the other kids at the same time.
Is he being assessed for additional needs? If so where are you for this?
There is a problem here. They will not allow a request without going through process first. Many schools will not initiate anything to do with additional needs until it hits a real crisis (this isn't one). They expect parents to initiate.
The school calling you like this, means you start making this a formal process. It doesn't sound like you are yet and tbh in yr2 it's unlikely anyway as they don't like to start them until age 6 anyway.
And a note of caution. Do you think the solution to not being able to cope in a school environment is going to be letting him run around at forest school and fall behind in other work? Do you not think this will lead to further disruptive behaviour?
How's he going to cope with situations later in life? He still needs to work on behaviour. Additional needs are not an excuse for poor behaviour. You still need to address the behaviour.
And from what youve said I suspect you havent really tried any in school options yet. Or got a diagnosis.
You need to start with soft options before going this far because it won't really deal with the underlying issues.
There may be other things you can do within the school setting first. The first is walking to school - this has actually been shown to make a massive difference to ADHD kids. Then there's time outs where he could do a supervised run around the playground if it all gets too much.
A managed forest school option only works if the school have a working relationship to do this and timetable everything around it. You certainly can't do this mid year. It's a long term discussion in partnership with the school over behaviour not a decision that parents make because of a singular trigger and enforce on the school. You will only end up at logger heads with the school.