What inconsistency are you referring to? I have no problems with my setup.I am assuming your draw length is very short or your arrows are very small spine if you’re getting 18% foc after dropping over 100 grains in the front. Is it possible it’s not the broadheads that are causing the inconsistency but perhaps your arrow is under spined for the speed you’re shooting? I ask this not knowing your draw length or draw weight.
But just for reference, I have a 29.5" draw length, arrows cut to 28", and am pulling 66#.