Not Perrin but:
You do light warmups up to about 60-70% of your working weight. You should have a decent idea of what it will be. You can always figure it out by testing your RPEs for max single and set of 5 and fill in a customized RPE chart for yourself. Once you get above 60-70% start working up in weight in sets of 8. You reach your top set when you get x8 @8 which means whatever weight you end up up you can do 8 reps with 2-3reps left in the tank. After that you drop the weight 6-9% for the fatigue percent. And since it says repeats for that particular lift, you repeat the 6-9% reduced weight until it too becomes RPE 8
So how many actual sets do I do in any of the cases? I get the working my way up but let's say I get to my 6 reps @9. Do I only do one more set after with the load drop? Also is there an actual chart you guys use I can look up or do you kinda just figure it out?