If you’re brewing at a constant grind setting for your method, you will be adjusting the grind to dial in for best flavour, sure. But low drip extractions have the same recogniseable faults, as do overly high extractions.
When you’re dialled, in your extractions will have a natural variation based on different coffee’s solubility, lower (but still normal) extractions will be fine, as will higher (but still normal extractions). Being able to measure it just saves a lot of time & exploring rabbit holes because you may have second guessed an issue that wasn’t extraction related.
You won’t be getting abnormally low, or high extractions.
In the absence of measurement, record taste scores and note the nature of any faults, both compared to grind setting.
16% drip extractions will not taste good, neither will those over 24% for the vast majority of people, though a normal span would be more like +/- 2% for 95/100 brews.
But also, focus more on the second part of my post, is the roast OK, are you introducing too much silt. Forgot to mention ensuring that you are recognising where your preferences lie, be aware of wasting too much time on origins that you may have low preference for,
