The AME was adamant mine had to be done. He was more concerned about me having asthma 20 years ago than he was at me squashing my left forearm in machinery 7 years ago which seemed to go relatively unquestioned.
In my opinion the referral there was a waste of time, after 7 minutes of a brisk run on the treadmill, barely breaking a sweat then blowing into the mouthpiece over 3 separate sessions I was free to go. I just took it on the chin as one of those hoops to jump through..
The admin staff there can be very condescending so I wish you luck!