@Mummy0ftwo12 my ds has autism / learning difficulties / speech delay / disorder, he has a full time 1-1 at school and an ehcp etc. (He doesn't receive salt at all though!)
He started school last September age 4 yr 8 months with the development age of 16-26m across the board.
He's now a mix bag of developing 30-50, some 40-60 emerging, with some areas (numbers and reading in particular) being nearly onto early learning goals. This is 13 months after getting 16-26m across the board.
He's nearly 6, so still obviously delayed but he does have quite obvious SN.
What I'm trying to say is, ds with his diagnosis has made a lot of progress since starting school, better than anyone expected to be honest. He can write his name, a few words, read some level 1 books. Last year he couldn't even hold a pencil!
School will do some initial assesments and give the support your dc requires, also I find school very different to nursery in terms of learning.
Ds just played all day at nursery, where as at school, he learns through play, but also does 'jobs' (that's what they call his work)