you buy the machine, feel free to use it how you please
but a common mistake is to pull the cup from the stream after the prescribed 27 seconds after it starts to flow, but then have the coffee run and drip for way too long beyond 27s
the flow should have stopped before you get to 35s after the flow started
if it is still dripping and dropping coffee out to say 50s your grind is too fine for the dose you are running
in my view you achieve the best taste when it starts to blond just at 27s after flow starts, you pull the cups, and you get a few seconds more of flow to say 30-32s, but then only the odd drip beyond that
run the pre infusion time until you get the first drip
enjoy your machine this weekend