I see someone else suggested changing the "Grid" rules. The age categories need to be increased upward. Given increases in nutrition and medical technology, as well as increases in retirement eligibility ages, I think it is unrealistic to consider an individual age 50 to be "approaching advanced age," and age 55 "advanced age."
With changes in the workplace, I also do not believe an older worker today is so economically disadvantaged by a restriction to "sedentary" work as to direct a finding of disability. This may have been the case in days past when so many jobs involved manufacturing and construction, but I do not believe limiting a 55 year old to sedentary work equates with disability in today's information- and service-centered economy.
The child's SSI program also needs considerable scrutiny. Whatever the original purposes of this program, at present it encourages many parents to have their children diagnosed with and treated for mental/emotional/behavioral conditions. While children in need should certainly have their eductional and medical needs provided for, I do not understand why the parent of a child who is already receiving subsidized medical and educational services should ALSO receive a monthly cash payment, with no restrictions on how those benefits are spent. There is no requirement of any sort that the child's SSI benefits be spent in any way related to the child's supposed "disability."
There are countless other tweaks that would be appropriate and would generate substantial savings in the disability program, but these are among the most obvious.