I will need to add up to 8-10 g of tip weight to these 70g .370 KBS PGI shafts with Miura k grind wedges (52,56,60) to achieve a D3-4 swing weight.  Will doing so stiffen the shaft tip significantly and should I soft step the shaft down to a 8 or 9 iron trimming to offset adding the rubber tungsten 8-12g weight?