That's a complicated thing to answer. Models of working in secondary are developing at the moment because traditionally, SLTs haven't worked there in this country.
We try to involve teachers by getting them to give us a programme of work in advance. We know the students best so we devise the strategies and then advise the teachers on what the students need. They will suggest a differentiation but often this amounts to "oh they can't do that, leave that out"
as they don't have anything else to throw at it. So we have to differentiate (unit co-ordinator who is HLTA and I). However, as we are not teachers, this is a circuitous route as we have to differentiate, take it to them to check it meets their objective, then make alterations and bring it back again.
The SENCo tends to take a more managerial role and doesn't really get involved in one setting.. in another they co-ordinate and get plans for me and we work together on groups etc.
I know how I work is very similar to what specialist advisory teachers for SLCN do in other areas.. but we don't have a team like that, so I have to take it on. I have met colleagues from other areas who are in the opposite position.
Where's the class teacher in all of this? Bloody good question! In my new role, I am trying to address the fact that what differentiation "looks like" in practice in many classrooms is a student with an adapted worksheet sitting with a support with limited subject knowledge at a table, locked out of learning within the supposedly "inclusive" classroom. It's not all bleak - I've seen some really good teaching too, but it's harder when you are talking about a high achieving student as often the teacher doesn't see what they need in a way they might with a lower ability student.
Teachers don't do it to exclude.. they just don't know where to begin so they find differentiated sheets for their programme of work online and hand that over to support staff to carry out. Support staff frequently have limited training or support in how to get that information across so they learn over time by a process of trial and error.
It's not good enough but in the new school I am currently working in (still also in my old one), there is huge enthusiasm and commitment to change - it's really not a case that they want to shirk their responsibilities, they just don't know what they're doing with students with specific needs smetimes. They have no real training in looking at the tasks they give in this way so the good ones have just picked it up by osmosis and even they need support when it comes to the subtleties you describe.
Some are keenly involved in joint working - I suggest a change/strategy for a student or how to differentiate something, they say yes but I need them to know x too how can we work on that, we come to an arrangement. This is when we have optimal outcomes. Some don't want to know and expect we will do it for them and see the students with SEN as "our" students
.
I am working HARD to get teachers who don't care to take responsibility. I have said all sorts of stern things about the Disability Discrimination Act and I spend a lot of time taking about how every teacher is a teacher of special needs and how it is their role etc. But in the meantime I'm not going to let my students flounder which sometimes means I do reinforce their bad behaviour... It means I have a very bizarre role because I can only adjust language and task demands and work on metacognitive stuff but I am not doing as effective a job as I feel my students need because I can't transmit the subtleties of the curriculum as I don't have the content knowledge. This is something I have had to argue with some staff who just don't understand the difference between being able to adjust the task structure and simplify language and actually TEACH because you know the ins and outs of the subject.
This is in a setting with a specialist resource. It can be much, much worse in some settings without these resources as they don't have the experience either. This is not true of all, of course, but it does sound as if your son's school believe that they are doing what's right because they have a fundamental lack of understanding of the issues because of their poor knowledge and experience of these issues.
I hope this isn't too depressing but I wanted to give you and idea of what it's like from the inside.
I think most teachers - the overwhelming majority - really want the best for the kids but they just feel lost and panic if they think that what you're asking them to do is going to add to their already heaving workload. They are asked to do a lot. In an inclusive classroom, they may have 7, 8 even 15 students who learn in different ways and all sorts of behavioural issues etc to deal with.