I have found pathways into further and higher education to be too linear, and that there is too much focus on choosing a profession at too young an age. We are asking young people to decide something before their brains are fully developed. I myself decided on a career at 18 that was totally wrong for me, and I disappointed my family, and the whole thing affected me for a long time.
My nephew is going through much the same thing. He knows what he'd like to do but he as been a bit aimless, and doesn't have the support to achieve his goals.
My brother, who is my nephew's dad has written off his son, but our dad wrote off my DB so it continues inter-generationally. I can't imagine how crushing that might feel like. OPs lad has additional SEN so it must be really hard.
I think young people need to try different things out for a short time to inspire them. Work experience at my DDs school was utter shite, only 2 weeks in the entire time she was there, including Y12 and 13. We should be getting kids to do more work experience and voluntary work to see what fits.
I think school is too focused on academia and the university pathway. My DDs school invites the local paper over during GCSE & A Level results days. What about the kids who have done well in their vocational qualifications? Not a bloody dicky bird.
Why can't this lad's father use his connections to get his son some work experience? Obviously the two of them don't work well together but there must be someone else in that world who is patient and good with new learners?
I would go on that apprenticeship website and see ALL the options, not just the manual trades. It might be that something new poos up that your son hasn't thought about before. I wish him the very best.
Edited for clarification