All paws and fingers crossed here that this protocol is effective.
On a side note, I lost my first Sheltie to something similar: dermatomyositis, also called bullous ulcerative dermatitis with basal cell necrosis. She tolerated Pred reasonably well for a couple of years, but it didn't keep the disease contained and the DM affected her organs. DM is an autoimmune disorder in Shelties that is heritable and often manifests in mid-life, as Briar Rose's did; vaccines can be the trigger, as they apparently were with her. I didn't know any better back then and she was vaxed annually.
Not saying this to be a debbie downer, sorry it reads like that.