if i understand correctly a power lam is used to make the mid limb do more work, and a tip wedge does the same thing but from the other direction, right? my next question is do you take the thickness of them into consideration when figuring lam thickness for draw weight purposes?
They help you concentrate the working limb portion to where you want it to be and control string angle. You don't count their thickness as part of the stack but you do have to consider their effectiveness into the stack recipe you go with. Using them will increase the draw weight for a particular stack.