At this point in time you don’t necessarily need the LA or the school to do or agree anything. DS is below CSA so you have the right to defer until later in the year or for him to attend part time if you wish.
Once DS is CSA if DS can’t attend school full time the LA must provide a suitable, full time education under s.19 of the Education Act 1996. This is much easier if the LA are on side, but is still possible if they aren’t because you can force them. A brief overview of the process would be email the Director of Children’s Services informing them of the situation and requesting provision. If they refuse, delay or ignore you email again threatening JR. If they refuse again contact SOSSEN for a pre-action letter. In the vast majority of cases where the LA initially refuse they back down when parents threaten JR or with a pre-action letter. Only a small minority get to a point where they have to begin proceedings.
In addition to the above you can apply for an EHCNA. You can do this now you don’t need to wait for DS to be CSA. IPSEA have a model letter you can use on their website. If school isn’t suitable an EHCP can include EOTAS rather than it naming a school. EOTAS packages are all different as they are tailored to individual needs but can include tuition, therapies, care farms, forest schools, mindjam, outdoor activity groups, sports, cooking lessons, other provision, mentor, a budget for trips out/resources/equipment… the possibilities are endless.
Again, the process is easier if the LA are onside but is still possible if they aren’t. Many parents do have to appeal during the EHCP process, some more than once, but it is worth it when all the support is in place. The majority of appeals are upheld.
DS1’s EOTAS package includes 1:1 tuition, therapies (SALT, OT, SIOT, play therapy, physio, Lego therapy, rebound therapy), ELSA, swimming and kayaking/climbing (enough funding for 1hr 1:1 of one or the other of them per week - DS1 normally does climbing in the winter and kayaking in the warmer weather). It also includes equipment, subscriptions/memberships, a budget for resources/outings/sundries. HLTA hours to act as the second adult outside the house/escort for transport. And professional time for meetings/reviews.