Do you mean a pressurized basket? It’s a regular 18g basket. I do have a pressurized basket but I don’t use it. The portafilter is a standard 58mm double spout portafilter, not bottomless but doesn’t add additional pressure or foaming. What you’re referring to is likely from the basket though, not the portafilter itself. AFAIK the portafilter bottom doesn’t affect crema at all, only the basket.

From what I’ve read, real crema comes from a good amount of pressure. How finely are you grinding your beans? And have you weighed and timed your shots? I’ve been having consistently good crema with the general guideline of double the output you put in (so in my case, 18g in, roughly 36g out) at around 25-35 seconds. My wife’s shot was 36.5g out in 29 seconds, mine was 37.0g out in 37 seconds (I was a bit late turning it off this morning, but oh well).