Really your goal should be matching effort throughout the ROM with these pieces. Think of this equipment as a tool such as the band or chains.
You have an opportunity to match the profile of the machine to your body which is what makes them unique.
For instance, the Prime Supported Row, 9/10 times almost of your load is going to go in the lengthened range (too peg). In the start of the range, the load is heaviest, and as you contract throughout the concentric range the load drops off more and more. This matches the profile of your back. Strong in the stretch, weak in the contraction.