TESA tribunal deferring final decision to DWP

My brother suffers from Chronic Cluster Headaches and has been in the ESA Support group for years. A medical earlier this year found him fit for work, but he appealed the decision and the tribunal found in his favour; The tribunal letter stated that he has limited capacity for work, but insufficient points were scored however if he were found capable of work it would result in substantial risk of deterioration of his condition. The tribunal deferred the final decision to the Secretary of State.

The DWP decided he had limited capacity for work but did NOT put him in the Support group so early next year his entitlement to ESA will cease.

There does not seem to be any further appeal and so it seems he has no option but to report to DWP and apply for employment, even though it will probably make his condition worse,

Does this happen often? Does anyone have experience of this or any suggestions?

His wife works, so if he moves from contribution based benefit he will be entitled to very little money. While this is concerning his principal concern is that the requirement to be available for work will have an adverse effect on his condition. If this happens can he reapply for ESA?

That is reassuring, that he will not be forced to apply for work. But it means the family income (not great right now) will drop alarmingly. Because his wife works as a nursery nurse it is unlikely that he will be eligible for much benefit when hie ESA stops. He has recently applied for and been granted PIP but that is less than half.
Any suggestions?