I’ll be telling the baristas amongst you what you will already know, but if you want maximum definition of the various tastes in the roast you need to dose in/around 15g for the LONDINIUM espresso machines
If you want the big gloopy impressive looking shots then dose higher, say 19g by all means, but it tends to become a bit more like mousse/syrupy gloop with the individual flavours more rolled up together to create a single average taste