I have an arm that finds the string, every time I shoot, I am just built that way. 60 years of shooting every conceivable way possible had convinced me to just live with it. I wear a thin cordura arm guard and shoot low stretch strings to minimize the slap which is a light sting if I shoot without my armguard. If I rotate things to get my arm out of the way my shooting accuracy sufferers greatly.
Growing up as a kid I had a BB gun that shot with a foot dogleg to the left at 20 yards, I didn't use the sights and shot instinctively, a starling head at 30 yards was in danger, I almost never missed, this dogleg was subconsciously imprinted into my brain. So it is with my arm slapping arrow trajectory, I shoot quite well in spite of it.