Very interested in ordering a set of 712 AP1s and am currently playing the KBS Tour 90 in a non-Titleist iron (players' iron between AP2 and AP1) and like the light weight and equate to a swing weight of D0. 710 AP1s are swing weight D1 and I am presuming 712's will be the same. If I am not ordering the stock shaft for 712 AP1s and want a similar type shaft to KBS Tour 90 (which are lighter), can swing weight be specified as D0 without impacting overall performance of iron?