RE: Significant Fletch Contact.
longer prongs would get it farther away from the base.
are you using the steel cable if so ditch it and get some string loop material and serve it on your down buss cable. Make sure the rest is coming all the way up only 1 to 2 inches from full draw.
if you hace the rest coming up too soon the rest dont have enough time to fall completley out of the way of the fletching.