I believe raising the brace height decreases the power stroke thus making a stiff shaft show even stiffer.I have raised the brace height on an arrow that shows alittle weak decreasing the power stroke,to make the arrow show stiffer.Like said you want a thinner side plate on a stiff arrow and you could try increasing point weight also.I you like the point weight,you can add weights behind the insert also.Would need more info,bow weight,draw length,what is your arrow set up now and what is it doing.