712 MB hosel insertion depth

can anyone explain the reasoning to why the shaft insertion depth are different on the 712 MB? the 8i-pw insertion depth is 1.270" and 3i-7i is 1.070". what does this accomplish? 

Shorter penetration depth allows the tip of the shaft to be more active and enhance launch. I'm not sure if this is Titleist's intention, but it will make the longer irons slightly more forgiving and launch them higher for softer landings on the green. The deeper shaft penetration in the shorter scoring clubs will enhance accuracy and improve trajectory and spin control. Varying hosel depths is not new and is a good way to enhance the playability of the set right out of the box for a typical muscleback player. 

can someone tell me the bbgm for 712 mb irons? or the exact measurements for bottom to top of hosel. I cant seem to get the exact measurements for trimming my shafts.