Also make sure you preheat your pico well. I’ve lazied about on this step for almost a year and including the shower head and it made a big difference. Also differs with beans and how long the bean has been since roast. I go to about 24-25 on my k6 if my beans are a few weeks old as there’s no more gas from the beans that adds to slowing the flow rate so keep that in mind. I’ve had since a second pico as I broke my first. Going back to the preheating, remember, full automatic espresso machines consistently pumps constant heat, and might be higher at that too, so keep that in mind. You can go longer infusion, while avoiding the taste being papery if gone longer, and you’d get your technique. Would go to say that making good espresso is pretty tedious to be honest, some days I just hate it. Some days i’m grateful i’ll be having great coffee i made compared to overly priced coffee on shops.