boren wrote:... They work ok, but I prefer a larger amount of coffee. 12 gram in the basket and 24 gram in the cup is what I normally want. No more, no less...

Have you considered the traditional 12g double basket with slanted sides? I have a Simonelli 12g slanted which I believe is no longer available, but IMS and LF make versions, e.g.,

https://www.imsfiltri.com/filtri/cf2t068/

The much more common LF 14g slanted basket is probably just a little taller than the 12g but otherwise identical. I'll try 12g in my 14g LF tomorrow and update.
https://coffeeaddicts.ca/products/porta ... c2b2&_ss=r

ETA: The LF 14g worked fine at 12g. I was wondering if there would be enough coffee to clear the slanted sides for tamping, and there was with the coffee that I used (Saka Gran Cafe, so a dark-roasted blend - although not Starbucks-dark). Of course there was more than ideal headspace, unlike a 12g basket. (The Strega was flushed to bring the brew temperature down, so the initial fill was slow and gentle. Bezzera does offer 12g and 14g baskets for the Strega.)

I'll leave the endless discussion of taste vs. basket design to others .

I've been able to fix donut channeling by reducing dose.

Update: I can confirm that the curved tamper base solved the problem. No more side channeling.