#1...use some proper string even for a long string
#2...shorten that long string up to where it just or almost touches the handle....your tiller might look different and I can't really say where you need to scrape because that angle of the string will be different on a shorter string or braced....but the right limbs outers are stiff and your getting a hinge just past the fade,and you shouldn't be pulling it that far..which leads to...
#3...never pull past a problem(hinge)area...even when on a long string...as you tiller and make more bows and your eye develops you'll be able to notice these areas easier and sooner,and know not to pull any further...yours isn't a huge problem,but its subtle