In a nutshell, if you are P and T, the VA can not reduce you unless you have had “material improvement” under ordinary condtions of life. The improvement can not be because of bed rest. They have to show you improved enough to go back to work. (Under ordinary conditions of life, as “ordinary people” work, but disabled people do not.)
Its VERY VERY tough for VA to reduce Vets who are P and T, UNLESS they go back to work.