Perhaps your problem is not LOP but proper shooting form and head position. I too am 6'3" and 200lbs. I had the same problem with the bruised cheek for many years. I tried shorter and longer lengths of pull and many types of pads but I still walked away after 100 rounds of trap or clays with a goose egg on my cheek.
It wasn't until I was told that I was bringing my face down to the gun rather than bringing the gun up to my face that the problem went away. When I lowered my head to the stock I cocked my head slightly to the right over the stock and every time I shot - BANG! And once that started it was difficult not to flinch on subsequent shots.
When I was taught to position my head and face properly on the stock, my eyes were horizontal to the ground, I saw and was able to pick up the birds much better and my scores went up and the pain factor went down immediately.
Try having somebody check your mount.
