I do 20g presses in a 2x4 inch bag on 3x5 plates. Rarely need to go over 4 tons of pressure. If you go over 5 tons, the rosin starts to get green, or plant matter is in the rosin. Not desired in my opinion.
Have you tried 20g of flower in your press? Maybe I’ll try it sometime, prepress into the puck, then press for the rosin.
I just pressed 100 grams of Sunshine Daydream, got 28.9 grams of rosin with bags, almost 29% yield, best I’ve seen in bags. I don’t do a second press, btw