I would add the tren to the 2nd hald of the cycle. Going from natural to "on", the primo and prop are going to dramtically ramp up anabolism and dramatically improve nutrient partitioning. Over the first several wks, this will just keep improving but as I'm sure you're aware, towards the end of the cycle, things would slowly become less productive as your body tries to find homeostasis. Adding in the tren will be like adding gas to a fire, ramping everything up.