Is it legal to not communicate about lessons that my son has missed due to neurodivergent related anxiety?

I would appreciate legal advice on the following situation.

My son is on SEN Support (SEMH) at a mainstream secondary school. He is in year 10. He has anxiety and neurodivergent-related burnout which has led to periods of reduced timetable and short-term absence.

The school states that learning takes place in school and does not routinely provide curriculum information when a pupil is absent. Teachers have declined to provide details of what was taught when my son has emailed to ask. The school does not use google classroom or equivalent.

The school has signposted ESMA (Educational Support for Medical Absence) as the route for structured learning outside school. However, we have been informed by school staff that anxiety linked to neurodivergence is unlikely to meet ESMA criteria, and that there is a waiting list in any event.

There appears to be no written procedure explaining how a pupil on SEN Support who is absent due to SEMH-related difficulties can access information about missed lessons, topics covered, or assessment preparation. Information has only been provided reactively and at the end of a half term (they provided a google doc with vague guidance that was meant to cover the previous 5 weeks worth of work when his attendance was 50%).

My questions are:

Is a mainstream secondary school required to have a clear procedure for curriculum access or catch-up for pupils on SEN Support who have disability-related absence?

Does a blanket position that “learning only happens in school” risk breaching the Equality Act 2010 duty to make reasonable adjustments where a pupil has recognised SEMH needs?

Is it sufficient for a school to direct parents to an external medical absence service (such as ESMA) where the pupil is unlikely to qualify?

In the absence of ESMA, what is the school’s legal duty to mitigate academic disadvantage during short-term disability-related absence or reduced timetable?

Would the lack of a written catch-up process potentially amount to a failure to use “best endeavours” under the SEND Code of Practice?

We are not seeking dual provision or home schooling. We are seeking clarity on what the school is required to do, and what we as parents are required to do, in order to support our child appropriately during periods of disability-related absence.