I have actually had to get my Neurosurgeon to write to them, and it will be interesting to see if they even reply to him,
When I lost my Class 2 medical because of leukemia the CAA warned me that it would be a long time before I could hope to restore it, if ever. Two months later, following a successful response to treatment, my oncologist sent a report to the CAA. The Chief Medical Officer then wrote to me restoring my medical which had not yet lapsed. I do not believe that they responded to the oncologist.
I can't help wondering that, as long as they have a professional medical opinion to rely on, they can be quite cooperative. Obviously it may be a lot tougher in the Class 1, commercial world.