Don't worry too much about the length of time for your preinfusion. If it's built in then it's all good - as long as it's consistent that's the main thing.
I'm very lucky with the coffee we have available here in New Zealand. Living in the capital, Wellington, we have fifteen roasters in a city of around 500,000 people. It's amazing, and means it's easy to try new flavours and roasts. I'm still relatively new to espresso (and New Zealand for that matter), so I tend to try whatever looks exciting and use it as a chance to learn. Either learning to craft the shot as close as I can to how it was served to me in the roastery, or learning to taste the differences between different blends and regions. It's all really exciting.
The coffees I keep coming back to are a wonderful Tadesse Meskela from Peru roasted by People's Coffee, all plums and cocoa on the finish, and the delicious Five Star by Havana Coffee Works which is a velvety chocolate and molasses in the cup. It's a deeply un-trendy comfort blend which I can't seem to get enough of!
That's a good point actually - the very first coffee I tried to dial in on my Breville was a decaf I'd never tried. I know, I know! What a moron! I had no idea what it was meant to taste like and no idea whether I was actually going to like the coffee. If you know you enjoy a specific bean or blend I'd start with that one when dialling in, then you know what it should taste like and what you're trying to recreate with your machine.
Sorry for rambling - I got over excited
I wish there were options around me but unfortunately, there is not. I live in an area where a cheesesteak joint started removing cheddar cheese from the 3-Cheese steak sandwich (provolone, Swiss, and cheddar) and replaced it with American cheese. "People like American better" is the response I got.
So you can imagine there is no market for high quality anything here.
I've learned in the past week that I will most definitely be using different beans for shots as I do for Flat Whites, Cappuccinos etc.
Something I never thought of before.
I brewed a couple shots of Lavazza Super Crema.
1) 15.5g , forgot to time, 31g out!!!! Finally the BR is good! Tasted Sour
2) Grind one click finer, 15.5g, 25sec, 38g out. Still sour but neither tasted at all weak or thin...
So I'm going to jack up the temp +2 degrees , grind 1 click finer and pull again to see if it un-sours the shot.
Changing two settings at once because I am not close enough to dial it in and tweak it.