For larger bore rifles, a few grains here and there are not super critical.

IMO for ML's and Black Powder or Synthetics, 5gr increment is about as precise as needed for most target and hunting load development for 45 cal and larger rifles.
That said, I sometimes use a combination of a 5gr and a single gr measure for inbetween charges.

Match shooters typically develop to the single grain load.

A 10gr increment measure is not precise enough in my view.

For pistol, a single grain measure is mandatory in my view.

Yes Nick, you can tap it with a finger or swing the funnel over the measure and end up with pretty much the same amount of powder. The trick is to do it the same each and every time.

You got it right. Fill the measure, tap the measure to settle the load, then sliding the spout closed knocks off the excess. Tapping the measure as you fill it will help with the consistency of the load.