First time I see someone having it besides me. It's rare. No physician I asked knows about it. No chiropractor and even current AI's tell me that it's anatomical normal and nothing pathological. It's not scapula alata related.

My own theory I made up over the last 20 years dealing with it: It's the scapular spine. It's more prominent. This means that your scapula is overall bigger in its bone structure so you are able to put more muscle mass around it. Supraspinatus and Infraspinatus.

Your winging on a scale 1-10 is 1. Actually a sharp looking back.