It's a Bezzera BZ10 PF with the stock double basket.
The bottomless PF I bought was also Bezzera brand.
I started with 20g dosing on the triple and had the same issues, which is when I went up to 24g to see if there was a difference. I'm not getting shower screen imprints on the 24g shots so I don't think it's too much. I have not tried the nickel test, however. The pucks have not had shower screen imprints yet so I think I could add even more before it hits.
Is there such thing as a quad basket?