For me the grinder allows repeatability. I was trying to dial in shots with the grinder on my breville and was quickly frustrated. I could do everything else the same and get very different extraction times for the same volume of espresso, I ran 5 lbs of coffee through it in a row with my laptop and a spreadsheet tracking things trying to get consistent times, and it just wouldn’t be consistent.

I bought a HG-1, probably overkill, but now my mid-range breville puts out coffee that is way way better than most cafes, and it’s dead consistent. I have to adjust a little as my fresh coffee adapts to the world once the bag is open, but that’s it.

I’m sure you could find calibrated screens for espresso somewhere, but my bet is they would cost more than a new grinder. If it’s consistent, tastes good, and you have fine enough settings to adjust your extraction, I’d say it’s good.